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Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course Workshop 12 “Simulators for Des

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					   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                                          Workshop 12
                         “Simulators for Design Across the Curriculum”
                         ASEE Summer School, Colorado, August 2002

Workshop Leaders: Daniel R. Lewin (DRL), Dept. of Chemical Engineering, Technion.
                  Warren D. Seider (WDS), Dept. of Chemical Engineering, Penn.

Workshop Objective: During the senior year design project, teams of students carry out an
integrated process design, determining its technical, environmental, safety, and economic
feasibility. Due to the problem scale, this inevitably involves the use of a process simulator to
formulate and solve the material and energy balances, with phase and chemical equilibria and
chemical kinetics, for cost estimation and economic evaluation. The availability of a reliable
process model allows the design team to assess rapidly the economic potential for alternative
designs, as well as to derive operating conditions using optimization methods that incorporate
economics. To ensure that students are prepared to meet the challenges of the design project,
they should be prepared for the competent and critical use of the process simulators. This is best
achieved by a gradual exposure to aspects of their use through various exercises in the core
courses. This workshop, which is intended for chemical engineering faculty, shows one way to
achieve this objective.

Contents: This document is an assembly of: (1) suggested instruction sequences, using the
multimedia CD-ROM (Using Process Simulators in Chemical Engineering: A Multimedia Guide
for the Core Curriculum), henceforth referred to as the multimedia, and (2) problem statements
and solutions for class exercises and projects using process simulators to support many of the
chemical engineering core courses. Materials are included for courses on: Material and Energy
Balances, Thermodynamics, Heat Transfer, Separation Principles, and Reactor Design. ASPEN
PLUS, HYSYS.Plant, BATCH PLUS, and IPE files used for the solutions of the exercises are
also available on this CD. In addition, each participant of Workshop 12 will receive a CD
Containing Version 1.2 of Using Process Simulators in Chemical Engineering: A Multimedia
Guide for the Core Curriculum.




                                               –1–
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

              Chemical Engineering Principles and Material and Energy Balances

HYSYS.Plant

        The materials supporting a course in material and energy balances assume that that at
least four hours of computer laboratory time is allocated to the exercises. A self-paced approach
using the multimedia allows the students to bring themselves “up-to-speed” on the use of a
process simulator to develop and solve material and energy balances of process flowsheets
involving simple models of unit operations and recycles. The following sequence of modules is
recommended:

Session 1: Under Principles of Process Flowsheet Simulation, access Getting Started in HYSYS
           (overview). Its main menu consists of four sections (1. Define the Fluid Package, 2.
           Set Up the Simulation, 3. Convergence of Simulation, and 4. Advanced Techniques).
           Students should review all three modules in the first section on the fluid package,
           and the first three modules in the second section on setting up the simulation.




Session 2: At this point, the student should be ready to construct and solve a relatively simple
           example. The first tutorial supporting a course in M&E balances, Ammonia/Water
           Separation, is appropriate. The student should follow the multimedia while at the
           same time develop his/her version of the simulation using HYSYS.Plant.




                                               –2–
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

Session 3: Begin by reviewing material learned so far – review the module “Do It Yourself (the
           fifth module under Getting Started in HYSYS - 2. Set Up the Simulation). Next
           briefly review the section Getting Started in HYSYS - 3. Convergence of Simulation,
           paying particular attention to the section on Recycle Implementation.




Session 4: At this point, the student should try to set up and solve a         flowsheet involving
           material recycle. The second tutorial supporting a course            in M&E balances,
           Ethylchloride Manufacture, is appropriate. The student              should follow the
           multimedia while at the same time develop his/her version of        the simulation using
           HYSYS.Plant.




Session 5: If additional time is available, the student can complete the review of materials
           supporting initial use of HYSYS.Plant, i.e., the remaining items in Getting Started in
           HYSYS - 3. Convergence of Simulation, and Getting Started in HYSYS - 4. Advanced
           Techniques. The most important features that should be covered are the materials
           that support for the use of the Spreadsheet and Databook, to assist in sensitivity
           analysis. If time is available, the student should also cover the use of Set and Adjust
           (in Part 3) and the Optimizer (in Part 4).

A project should be assigned to groups of up to three students, to reinforce their acquired
capabilities. A typical project definition is provided.




                                               –3–
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

               Chemical Engineering Principles and Material and Energy Balances

ASPEN PLUS

        The materials supporting a course in material and energy balances assume that that at
least four hours of computer laboratory time is allocated to the exercises. A self-paced approach
using the multimedia allows the students to bring themselves “up-to-speed” on the use of a
process simulator to develop and solve material and energy balances of process flowsheets
involving simple models of unit operations and recycles. The following sequence of modules is
recommended. Note that this sequence has not been class-tested using ASPEN PLUS. However,
a similar sequence using HYSYS.Plant, on the previous two pages, has been class-tested
successfully:

Session 1:   Under Principles of Process Flowsheet Simulation, access Getting Started in ASPEN
             PLUS (overview). Its main menu consists of five sections (1. Brief Introduction, 2.
             Setting Up, 3. Convergence, 4. Sensitivity Analysis, and 5. Sample Problem).
             Students should review modules 1-3 and 5.




Session 2:   At this point, the student should be ready to construct and solve a relatively simple
             example. The first tutorial supporting a course in M&E balances, Ammonia/Water
             Separation, is appropriate. The student should follow the multimedia while at the
             same time develop his/her version of the simulation using ASPEN PLUS.




                                               –4–
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

Session 3: Briefly review the section ASPEN -Getting Started - 3. Convergence, paying
           particular attention to the section on Recycle.




Session 4: At this point, the student should try to set up and solve a flowsheet involving
           material recycle. The second tutorial supporting a course in M&E balances,
           Ethylchloride Manufacture, is appropriate. The student should follow the
           multimedia while at the same time develop his/her version of the simulation.




Session 5:   If additional time is available, the student can complete the review of materials
             supporting initial use of ASPEN PLUS, i.e., the remaining items in ASPEN - Getting
             Started - 3. Convergence (especially, Control Blocks), and ASPEN - Getting Started
             - 4. Sensitivity Analysis.

A project should be assigned to groups of up to three students, to reinforce their acquired
capabilities. A typical project definition is provided. Three homework problems are suggested:
(Exercise A.1) (Exercise A.2) (Exercise A.3)


BATCH PLUS

       BATCH PLUS, an Aspen Tech product, carries out material and energy balances for
batch plants and prepares operating schedules (Gantt charts). In the second edition of SSL, we
have added material on the synthesis of a process to manufacture tissue plasminogen activator
(tPA). Then, a simulation of the tPA process is carried out using BATCH PLUS. For a course
on chemical engineering principles and material and energy balances at the sophomore level, this
material could be presented with the exercise provided below. The file TPA SYNTHESIS.PDF
provide the text that covers the synthesis and simulation steps.
                                               –5–
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                             Material and Energy Balances – Example Project

           Methanol is manufactured in a “synthesis loop,” in which a mixture of carbon
    dioxide and hydrogen is reacted to form the methonal product at high pressure:
                                           →
                              CO 2 + 3 H 2    CH 3OH + H 2 O
                                           ←
                                                                 S-6
                                                            Adiabatic
                                            Heater          Converter
                         Feed 500C    S-1            S-2                S-3
                                                                                  S-5
                             Ps                  400 C 0                                     Purge



                                            Cooler                       Ts
                                                           S-4                      Separator




                                                                                        Product



       The synthesis gas fed to the process, illustrated above, is largely composed of hydrogen
and carbon dioxide, but with traces of inert gases as in Table 1. Additional specifications for the
process are:
       SRK property predictions should be employed
       Pressure drops is all units can be neglected
       Converter feed temperature is set to 400 oC
       The converter can be approximated as a conversion reactor, operating
       adiabatically.
       The reactor conversion depends of the operating pressure, according to Table 2.
       The reactor effluent is cooled to a temperature of TS using a cooler, and fed to a
       flash unit, modeled by a separator.

                          Table 1. Process feed stream specification.
              Composition ( mol %)              Hydrogen 74.85
                                          Carbon dioxide 24.95
                                                     CH4 0.1
                                                    Argon 0.1
                                     Flow rate (kgmol/hr) 1000
                                        Temperature (oC) 50
                                          Pressure (MPa) PS

                          Table 2. Conversion as a function of pressure
              PS [MPa]         CO2 conversion [%]                      PS [MPa]          CO2 conversion [%]
                  5.0                 28.0                               20.0                   35.5
                  7.5                 29.5                               22.5                   37.0
                 10.0                 31.0                               25.0                   38.5
                 12.5                 32.5                               30.0                   40.0
                 15.0                 34.0

                                                      –6–
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

Your tasks:
   1. Solve the material and energy balances for the flowsheet for a purge flow rate of 600
       kg/h, and values for PS and TS by group, according to Table 3. Ensure an accuracy of 3
       significant figures.

                       Table 3. Operating specifications by student group.
      Group No.        TS (°C)        PS (MPa)              Group No.   TS (°C)      PS (MPa)
          1               10                                   16          10
          2               20                    5.0            17          20           17.5
          3               30                                   18          30
          4               10                                   19          10
          5               20                    7.5            20          20           20.0
          6               30                                   21          30
          7               10                                   22          10
          8               20               10.0                23          20           22.5
          9               30                                   24          30
         10               10                                   25          10
         11               20               12.5                26          20           25.0
         12               30                                   27          30
         13               10                                   28          10
         14               20               15.0                29          20           30.0
         15               30                                   30          30

   2. An operating window for the process is defined by a closed polygon in TS –Purge space,
      within which, the following constraints are met:
                                    200 < Purge < 1000 kg/h
                                            0 < TS < 40oC
                                     Mass flow rate of recycle ≤ 35 T/hr
                               CO2 mol. fraction in product ≤ 2.5 mol %
                     Mass flow rate of methanol in product ≥ 7,200 kg/hr

       Determine the operating window for the operating pressure for your group in Table 3. Try
       and estimate the limits of the operating window as accurately as possible, and plot the
       result as a function of TS and Purge flow rate, as shown below.




                                                      Operating
                                      Ts [oC]




                                                      Window

                                                      Purge [kg/h]



                                            HYSYS.Plant Solution


                                                      –7–
Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course


             Exercise A.1 Flash with Recycle Problem (Exercise 3.1, SSL)


    a.     Consider the flash separation process shown below:




           If using ASPEN PLUS, solve all three cases using the MIXER, FLASH2,
           FSPLIT, and PUMP subroutines and the RK-SOAVE option set for
           thermophysical properties. Compare and discuss the flow rates and
           compositions for the overhead stream produced by each of the three cases.

    b.     Modify Case 3 of Exercise 3.1a to determine the flash temperature
           necessary to obtain 850 lb/hr of overhead vapor. If using ASPEN PLUS, a
           design specification can be used to adjust the temperature of the flash drum
           to obtain the desired overhead flow rate.

                                 ASPEN PLUS Solution




                                            –8–
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

            Exercise A.2 Ammonia Synthesis Loop Problem (Example 4.3, SSL)


        For the ammonia process in Example 4.3, consider operation of the reactor at 932° F and
400 atm. Use a simulator to show how the product, recycle, and purge flow rates, and the mole
fractions of argon and methane, vary with the purge-to-recycle ratio. How do the power
requirements for compression increase?

Example 4.3 Ammonia Process Purge
       In this example, the ammonia reactor loop:




is simulated using ASPEN PLUS to examine the effect of the purge-to-recycle ratio on the purge
stream and the recycle loop. For the ASPEN PLUS flowsheet below, the followingspecifications
are made:
              Simulation Unit         Subroutine     T,°F            P,atm
                      R1              REQUIL         932             200
                      F1              FLASH2         -28             136.3


and the Chao-Seader option set is selected to estimate the thermophysical properties. Note that
the REQUIL subroutine calculates chemical equilibria at the temperature and pressure specified,
as discussed in the REQUIL module on the multimedia CD-ROM.
       The combined feed stream, at 77° F and 200 atm, is comprised of:


                                      lbmole/hr         Mole fraction
                      H2                24                 0.240
                      N2                74.3               0.743
                      Ar                 0.6               0.006
                      CH4                1.1               0.011
                                       100.0               1.000

                                    ASPEN PLUS Solution


                                               –9–
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

       Exercise A.3 Near-isothermal Distillation (Cavett) Problem (Exercise 3.7, SSL)

       A near-isothermal distillation process, having multiple recycle loops formulated by R. H.
Cavett (Proc. Am. Petrol. Inst., 43, 57 (1963)), has been used extensively to test tearing,
sequencing, and convergence procedures. Although the process flowsheet requires compressors,
valves, and heat exchangers, a simplified ASPEN PLUS flowsheet is (excluding the recycle
convergence units):




In this form, the process is the equivalent of a four-theoretical-stage, near-isothermal distillation
(rather than the conventional near-isobaric type), for which a patent by A. Gunther (U.S. Patent
3,575,077, April 13, 1971) exists. For the specifications shown on the flowsheet, use a process
simulator to determine the component flow rates for all streams in the process.


                                     ASPEN PLUS Solution




                                               – 10 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course


         Exercise A.4 Scheduling Batch Reactors Problem (New Exercise 4.19, SSL)


       Debottlenecking Reactor Train. To prepare for this exercise, read the background
materials in TPA SYNTHESIS.PDF. These new sections are for the second edition of SSL.

        When the third tPA cultivator in Section 3.4 is added to the two cultivators in Example
4.1, as shown in Figure 4.25a, a significant time strain is placed on the process because the
combined feed, cultivation, harvest, and cleaning time in this largest vessel is long and rigid.
Consequently, the remainder of the process is designed to keep this cultivator in constant use, so
as to maximize the yearly output of product. Note that, in many cases, when an equipment item
causes a bottleneck, a duplicate is installed so as to reduce the cycle time.

        For this exercise, the third cultivator is added to the simulation in Example 4.1, with the
specifications for the mixer, filter, holding tank, heat exchanger 1, and first two cultivators
identical to those in Example 4.1. After the cultivation is completed in Cultivator 2, its cell mass
is transferred as inoculum to Cultivator 3 over 0.5 day. Then, the remaining media from the
mixing tank is heated to 37°F and added over 1.5 day, after which cultivation takes place over
eight days. Immediately after the transfer from Cultivator 2 to Cultivator 3, Cultivator 2 is
cleaned-in-place using 600 Kg of water over 20 hours. The yield of the cultivation in Cultivator 3
is 11.4 wt% tPA-CHO cells, 7.7 × 10-5 wt% endotoxin, 88.9 wt% water, and 0.0559 wt% tPA.
When the cultivation is completed in Cultivator 3, its contents are cooled in a heat exchanger to
4°C and transferred to the centrifuge holding tank over one day, and Cultivator 3 is cleaned using
600 Kg of water over 67 hours and sterilized using the procedure for Cultivators 1 and 2.

        To eliminate an undesirable bottleneck(s), and reduce the cycle time to 14 days (total
operation time of Fermenter 3), it may be necessary to add an equipment unit(s).

       Print and submit the text recipes and 3-batch schedules for both the original process and
the modified process, if debottlenecking is necessary, as prepared by BATCH PLUS.


                                 For background materials and
                                  BATCH PLUS solution, see
                                   TPA SYNTHESIS.PDF




                                               – 11 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

Material and Energy Balances – Solution Sketch of Example Project using HYSYS.Plant

   1. The flowsheet is set up and its material and energy balance solved using HYSYS.Plant is
       a straight-forward fashion. A sample solution file is given as METHANOL_PART1.hsc.


   2. The second part of the problem is more interesting. This involves the use of the
       Spreadsheet, to generate Boolean variables corresponding to the feasibility of each of the
       three constraints:
                      Recycle: Mass flow rate of recycle ≤ 35 T/hr
                      Purity: CO2 mol. fraction in product ≤ 2.5 mol %
                      Production: Mass flow rate of methanol in product ≥ 7,200 kg/hr


      Subsequently, the Databook is used to construct 3D plots involving the Boolean variables
      as a function of TS and Purge. Sample operating windows in TS –Purge space, for
      flowsheets designed for PS = 5 and 30 MPa are shown in Figure 1, noting that the
      interpretation of the operating widows is given schematically in Figure 2. In general, the
      recycle and production constraints lead to lower and upper limits on the allowed purge
      flow rate, both of which are relatively independent on the separation temperature, TS. In
      constrast, the purity constraint leads to a lower limit on TS, whose value increases with
      increasing purge flow rate. As seen in Figure 1, the operating window is significantly
      more limited for operation at lower pressures. The files METHANOL_PART2_05.hsc
      and METHANOL_PART2_30.hsc provide sample solutions.




                           (a)                                       (b)
                 Figure 1: Operating windows for (a) PS = 5 MPa; (b) PS = 30 MPa



                                              – 12 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course


                               TS
                                               40 oC




                                         Operating Window
                                                                  Purity




                                                            Production


                                    Recycle
                                               0 oC
                                                                     Purge

               Figure 2: Interpretation of constraints bounding the operating window.

       The selection of operating point should consider the cost of energy, which increases
significantly as TS decreases, and the equipment costs, which increase exponentially with
decreasing purge flow rate. An appropriate choice would be at the top right-hand corner of the
operating window.




                                                 – 13 –
      Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                              Exercise A.1 Solution using ASPEN.PLUS

3.1       a.     ASPEN PLUS Flowsheet – simulation results can be reproduced using the
                                        file EXER3-1A.BKP on the CD-ROM.




                                                                      VP


                   FEED1                                                   F1
                                      M1
                   FEED2                              S2



                                 S5
                                                                      S3




                                                                S4         LP
                                                                      S1

                                           P1



                 ASPEN PLUS Simulation Flowsheet
                                                                                VP



  FEED1                                                    S2
                               M1                                             F1
  FEED2                      MIXER                                          FLASH2



                                   S5                                                S3


                                                S4*                  S4      S1                   LP
                              P1                       $OLVER01
                             PUMP                                          FSPLIT




                                                      – 14 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

               ASPEN PLUS Program

IN-UNITS ENG
                  DEF-STREAMS CONVEN ALL
                  DATABANKS PURE93 / AQUEOUS / SOLIDS / INORGANIC / &
                       NOASPENPCD
                  PROP-SOURCES PURE93 / AQUEOUS / SOLIDS / INORGANIC
                  COMPONENTS
                    METHANE CH4 METHANE /
                    ETHANE C2H6 ETHANE /
                    PROPANE C3H8 PROPANE /
                    N-BUTANE C4H10-1 N-BUTANE /
                    1-BUTENE C4H8-1 1-BUTENE /
                    1,3-BUTA C4H6-4 1,3-BUTA
                  FLOWSHEET
                    BLOCK M1 IN=S5 FEED2 FEED1 OUT=S2
                    BLOCK F1 IN=S2 OUT=VP S3
                    BLOCK S1 IN=S3 OUT=LP S4
                    BLOCK P1 IN=S4 OUT=S5
                  PROPERTIES RK-SOAVE
                  PROP-DATA RKSKIJ-1
                    IN-UNITS ENG
                    PROP-LIST RKSKIJ
                    BPVAL METHANE ETHANE -7.8000000E-3
                    BPVAL METHANE PROPANE 9.00000000E-3
                    BPVAL METHANE N-BUTANE 5.60000000E-3
                    BPVAL ETHANE PROPANE -2.2000000E-3
                    BPVAL ETHANE N-BUTANE 6.70000000E-3
                    BPVAL ETHANE METHANE -7.8000000E-3
                    BPVAL PROPANE ETHANE -2.2000000E-3
                    BPVAL PROPANE N-BUTANE 0.0
                    BPVAL PROPANE METHANE 9.00000000E-3
                    BPVAL N-BUTANE ETHANE 6.70000000E-3
                    BPVAL N-BUTANE PROPANE 0.0
                    BPVAL N-BUTANE METHANE 5.60000000E-3
                    BPVAL N-BUTANE 1-BUTENE -4.8000000E-3
                    BPVAL N-BUTANE 1,3-BUTA 8.10000000E-3
                    BPVAL 1-BUTENE N-BUTANE -4.8000000E-3
                    BPVAL 1-BUTENE 1,3-BUTA -4.4000000E-3
                  STREAM FEED1
                    SUBSTREAM MIXED TEMP=85 <C> PRES=100
                    MASS-FLOW METHANE 50 / ETHANE 100 / PROPANE 700
                  STREAM FEED2
                    SUBSTREAM MIXED TEMP=85 <C> PRES=100
                    MOLE-FLOW N-BUTANE 15 / 1-BUTENE 21 / 1,3-BUTA 95
                  BLOCK M1 MIXER
                  BLOCK S1 FSPLIT
                    FRAC S4 0.5
                  BLOCK F1 FLASH2
                    PARAM TEMP=5 <C> PRES=25
                  BLOCK P1 PUMP
                    PARAM PRES=100



               Calculation Sequence
                   SEQUENCE USED WAS:
                    $OLVER01 P1 M1 F1 S1
                    (RETURN $OLVER01)




                                              – 15 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

Stream Variables


FEED1 FEED2 LP S2 S3
--------------------

 STREAM ID                  FEED1        FEED2         LP         S2           S3
 FROM :                     ----         ----          S1         M1           F1
 TO   :                     M1           M1            ----       F1           S1

 SUBSTREAM: MIXED
 PHASE:                  VAPOR           VAPOR         LIQUID      MIXED       LIQUID
 COMPONENTS: LBMOL/HR
   METHANE                3.1166          0.0      2.1961-02        3.1386   4.3923-02
   ETHANE                 3.3256          0.0         0.1616        3.4872      0.3232
   PROPANE               15.8742          0.0         2.7989       18.6731      5.5978
   N-BUTANE               0.0            15.0000      6.8587       21.8587     13.7175
   1-BUTENE               0.0            21.0000      9.0466       30.0466     18.0932
   1,3-BUTA               0.0            95.0000     41.5243      136.5243     83.0487
 TOTAL FLOW:
   LBMOL/HR              22.3165       131.0000      60.4122      213.7286    120.8245
   LB/HR                850.0000      7188.8147    3280.9932     1.1320+04   6561.9864
   CUFT/HR             1472.6295      8135.3222      84.7851     8814.7421    169.5702
 STATE VARIABLES:
   TEMP    F            185.0000        185.0000       41.0000    126.7191     41.0000
   PRES    PSI          100.0000        100.0000       25.0000    100.0000     25.0000
   VFRAC                  1.0000          1.0000        0.0         0.7434      0.0
   LFRAC                  0.0             0.0           1.0000      0.2565      1.0000
   SFRAC                  0.0             0.0           0.0         0.0         0.0
 ENTHALPY:
   BTU/LBMOL          -4.0234+04      2.9758+04    1.3635+04     1.7911+04   1.3635+04
   BTU/LB             -1056.3433       542.2708     251.0564      338.1758    251.0564
   BTU/HR             -8.9789+05      3.8983+06    8.2371+05     3.8281+06   1.6474+06
 ENTROPY:
   BTU/LBMOL-R          -53.9876        -41.3689    -63.1321      -48.0510    -63.1321
   BTU/LB-R              -1.4174         -0.7538     -1.1624       -0.9072     -1.1624
 DENSITY:
   LBMOL/CUFT          1.5154-02      1.6103-02         0.7125   2.4247-02      0.7125
   LB/CUFT                0.5772         0.8836        38.6977      1.2841     38.6977
 AVG MW                  38.0883        54.8764        54.3100     52.9634     54.3100


 S4 S5 VP
 --------

 STREAM ID                  S4           S5            VP
 FROM :                     S1           P1            F1
 TO   :                     P1           M1            ----

 SUBSTREAM: MIXED
 PHASE:                     LIQUID       LIQUID        VAPOR
 COMPONENTS: LBMOL/HR
   METHANE                2.1961-02   2.1961-02         3.0947
   ETHANE                    0.1616      0.1616         3.1639
   PROPANE                   2.7988      2.7988        13.0753
   N-BUTANE                  6.8587      6.8587         8.1411
   1-BUTENE                  9.0466      9.0466        11.9533
   1,3-BUTA                 41.5243     41.5243        53.4756
 TOTAL FLOW:
   LBMOL/HR                 60.4121     60.4121      92.9041
   LB/HR                  3280.9860   3280.9860    4757.8142
   CUFT/HR                  84.7849     84.9629    1.9089+04
 STATE VARIABLES:
   TEMP    F                41.0000      42.9764       41.0000
                                              – 16 –
  Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

  PRES    PSI                 25.0000    100.0000         25.0000
  VFRAC                        0.0         0.0             1.0000
  LFRAC                        1.0000      1.0000          0.0
  SFRAC                        0.0         0.0             0.0
ENTHALPY:
  BTU/LBMOL              1.3635+04      1.3701+04    1.2859+04
  BTU/LB                  251.0555       252.2685     251.0950
  BTU/HR                 8.2371+05      8.2769+05    1.1947+06
ENTROPY:
  BTU/LBMOL-R             -63.1321      -63.0428      -44.6262
  BTU/LB-R                 -1.1624       -1.1607       -0.8714
DENSITY:
  LBMOL/CUFT                   0.7125      0.7110    4.8669-03
  LB/CUFT                     38.6977     38.6166       0.2492

AVG MW                        54.3100     54.3100         51.2120


             Selected Process Unit Output

BLOCK: F1        MODEL: FLASH2
------------------------------
  INLET STREAM:          S2
  OUTLET VAPOR STREAM:   VP
  OUTLET LIQUID STREAM: S3
  PROPERTY OPTION SET:   RK-SOAVE        STANDARD RKS EQUATION OF STATE

                        ***    MASS AND ENERGY BALANCE        ***
                                        IN                    OUT           RELATIVE DIFF.
   TOTAL BALANCE
      MOLE(LBMOL/HR)                  213.729              213.729          0.132980E-15
      MASS(LB/HR   )                  11319.8              11319.8         -0.299808E-10
      ENTHALPY(BTU/HR     )          0.382808E+07         0.284209E+07      0.257568

                          ***       INPUT DATA      ***
  TWO    PHASE TP FLASH
  SPECIFIED TEMPERATURE F                                            41.0000
  SPECIFIED PRESSURE     PSI                                         25.0000
  MAXIMUM NO. ITERATIONS                                             30
  CONVERGENCE TOLERANCE                                               0.00010000


                           *** RESULTS      ***
  OUTLET TEMPERATURE       F                                               41.000
  OUTLET PRESSURE          PSI                                             25.000
  HEAT DUTY                BTU/HR                                        -0.98599E+06
  VAPOR FRACTION                                                          0.43468



  V-L PHASE EQUILIBRIUM :

     COMP                 F(I)              X(I)                Y(I)              K(I)
     METHANE             0.14685E-01       0.36352E-03         0.33311E-01        91.633
     ETHANE              0.16316E-01       0.26757E-02         0.34056E-01        12.728
     PROPANE             0.87369E-01       0.46330E-01         0.14074            3.0378
     N-BUTANE            0.10227           0.11353             0.87630E-01       0.77185
     1-BUTENE            0.14058           0.14975             0.12866           0.85920
     1,3-BUTA            0.63877           0.68735             0.57560           0.83742




                                              – 17 –
  Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

      The results above are for Case 1 (50% bottoms recycle) in Figure 3.11. For Cases 2
   (25% bottoms recycle) and 3 (no recycle), the vapor and liquid product streams are
   identical to those for Case 1. That is, the product streams and the heat removed from
   the flash vessel are identical regardless of the amount of recycle. This is because the
   vapor and liquid product streams are in phase equilibrium at the conditions of the flash
   vessel.

        Acyclic Simulation Flowsheet

      Since the product streams do not change with recycle flow rate, they can be
   computed at the conditions of the flash vessel. Then, given the recycle fraction, the
   other streams can be computed. This is accomplished using the following ASPEN
   PLUS simulation flowsheet.
                                                                         MUL2          S3
                                                                         MULT
                                                 VP



FEED1
          MIX1                D1                  F1                     MUL1          S4      P1        S5    M1     S2
FEED2     MIXER                                 FLASH2                   MULT                 PUMP            MIXER
                      S1     DUPL        S1A

                                                      LP

                                                            LPB
                               S1B                D2
                                                 DUPL
                                                              LPA




                  Using this flowsheet, identical results are obtained.

   3.1        b.      ASPEN PLUS Flowsheet – identical to that in Exer. 3.1a. The recycle
   flow rate is zero.

                  Simulation results can be reproduced using the file EXER3-1B.BKP on the CD-
                  ROM.

                  ASPEN PLUS Simulation Flowsheet
                                                                                                  850 lb/hr


                                                                              FT
                                                                                       $OLVER02
                                                                    VP


            FEED1                         S2                 S2*                   T
                                M1                                    F1
                                               $OLVER01             FLASH2
            FEED2             MIXER



                                    S5                                   S3


                                                  S4                  S1               LP
                               P1
                              PUMP                                  FSPLIT




                                                           – 18 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

    ASPEN PLUS Program – identical to that in Exer. 3.1a with following change and
    addition:
                  BLOCK S1 FSPLIT
                  FRAC S4 0

                  DESIGN-SPEC OVHD
                  DEFINE OVHD STREAM-VAR STREAM=VP SUBSTREAM=MIXED &
                  VARIABLE=MASS-FLOW
                  SPEC "OVHD" TO "850"
                  TOL-SPEC "0.01 "
                  VARY BLOCK-VAR BLOCK=F1 VARIABLE=TEMP SENTENCE=PARAM
                  LIMITS "0" "100"

              Calculation Sequence

                  SEQUENCE USED WAS:
                     $OLVER01 *P1 M1
                     | $OLVER02 F1
                     | (RETURN $OLVER02)
                     | S1
                      (RETURN $OLVER01)



              Stream Variables

 FEED1 FEED2 LP S2 S3
 --------------------
STREAM ID                  FEED1        FEED2        LP             S2          S3
 FROM :                     ----         ----         S1             M1          F1
 TO   :                     M1           M1           ----           F1          S1

 SUBSTREAM: MIXED
 PHASE:                  VAPOR           VAPOR           LIQUID      VAPOR       LIQUID
 COMPONENTS: LBMOL/HR
   METHANE                3.1166          0.0             0.2336      3.1166      0.2336
   ETHANE                 3.3256          0.0             1.3166      3.3256      1.3166
   PROPANE               15.8742          0.0            11.8773     15.8742     11.8773
   N-BUTANE               0.0            15.0000         13.9004     15.0000     13.9004
   1-BUTENE               0.0            21.0000         19.2870     21.0000     19.2870
   1,3-BUTA               0.0            95.0000         87.4743     95.0000     87.4743
 TOTAL FLOW:
   LBMOL/HR              22.3165       131.0000      134.0894       153.3165    134.0894
   LB/HR                850.0000      7188.8147     7188.8082      8038.8147   7188.8082
   CUFT/HR             1472.6295      8135.3222      184.0987      9621.0871    184.0987
 STATE VARIABLES:
   TEMP    F            185.0000        185.0000         24.4944    184.7458     24.4944
   PRES    PSI          100.0000        100.0000         25.0000    100.0000     25.0000
   VFRAC                  1.0000          1.0000          0.0         1.0000      0.0
   LFRAC                  0.0             0.0             1.0000      0.0         1.0000
   SFRAC                  0.0             0.0             0.0         0.0         0.0
 ENTHALPY:
   BTU/LBMOL          -4.0234+04      2.9758+04     1.0003+04      1.9570+04   1.0003+04
   BTU/LB             -1056.3433       542.2708      186.5833       373.2382    186.5833
   BTU/HR             -8.9789+05      3.8983+06     1.3413+06      3.0004+06   1.3413+06
 ENTROPY:
   BTU/LBMOL-R          -53.9876        -41.3689     -64.4340       -42.3843    -64.4340
   BTU/LB-R              -1.4174         -0.7538      -1.2018        -0.8083     -1.2018
 DENSITY:
   LBMOL/CUFT          1.5154-02      1.6103-02           0.7283   1.5935-02      0.7283
   LB/CUFT                0.5772         0.8836          39.0486      0.8355     39.0486

                                                – 19 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

 AVG MW                     38.0883        54.8764         53.6120       52.4327   53.6120

 S4 S5 VP
 --------
 STREAM ID                  S4             S5              VP
 FROM :                     S1             P1              F1
 TO   :                     P1             M1              ----

 SUBSTREAM: MIXED
 PHASE:                     MISSING        MISSING         VAPOR
 COMPONENTS: LBMOL/HR
   METHANE                     0.0          0.0             2.8829
   ETHANE                      0.0          0.0             2.0090
   PROPANE                     0.0          0.0             3.9969
   N-BUTANE                    0.0          0.0             1.0995
   1-BUTENE                    0.0          0.0             1.7129
   1,3-BUTA                    0.0          0.0             7.5256
 TOTAL FLOW:
   LBMOL/HR                    0.0          0.0           19.2270
   LB/HR                       0.0          0.0          850.0064
   CUFT/HR                     0.0          0.0         3852.4889

STATE VARIABLES:
   TEMP    F                MISSING        MISSING         24.4944
   PRES    PSI              MISSING       100.0000         25.0000
   VFRAC                    MISSING        MISSING          1.0000
   LFRAC                    MISSING        MISSING          0.0
   SFRAC                    MISSING        MISSING          0.0
 ENTHALPY:
   BTU/LBMOL                MISSING        MISSING -3598.6336
   BTU/LB                   MISSING        MISSING   -81.4008
   BTU/HR                   MISSING        MISSING -6.9191+04
 ENTROPY:
   BTU/LBMOL-R              MISSING        MISSING      -43.0246
   BTU/LB-R                 MISSING        MISSING       -0.9732
 DENSITY:
   LBMOL/CUFT               MISSING        MISSING      4.9908-03
   LB/CUFT                  MISSING        MISSING         0.2206
 AVG MW                     MISSING        MISSING        44.2088


              Selected Process Unit Output

BLOCK: F1        MODEL: FLASH2
------------------------------
  INLET STREAM:          S2
  OUTLET VAPOR STREAM:   VP
  OUTLET LIQUID STREAM: S3
  PROPERTY OPTION SET:   RK-SOAVE          STANDARD RKS EQUATION OF STATE

                         ***     MASS AND ENERGY BALANCE           ***
                                          IN                       OUT        RELATIVE DIFF.
    TOTAL BALANCE
       MOLE(LBMOL/HR)                   153.317              153.317         -0.185379E-15
       MASS(LB/HR   )                   8038.81              8038.81         -0.138062E-11
       ENTHALPY(BTU/HR     )           0.300039E+07         0.127212E+07      0.576015

                           ***         INPUT DATA    ***
   TWO    PHASE TP FLASH
   SPECIFIED TEMPERATURE F                                                 24.4945
   SPECIFIED PRESSURE     PSI                                              25.0000
   MAXIMUM NO. ITERATIONS                                                  30
   CONVERGENCE TOLERANCE                                                    0.00010000

                                 ***    RESULTS   ***
                                                  – 20 –
Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

OUTLET TEMPERATURE       F                                          24.494
OUTLET PRESSURE          PSI                                        25.000
HEAT DUTY                BTU/HR                                   -0.17283E+07
VAPOR FRACTION                                                     0.12541


V-L PHASE EQUILIBRIUM :

   COMP                 F(I)             X(I)              Y(I)             K(I)
   METHANE             0.20328E-01      0.17428E-02       0.14994           86.038
   ETHANE              0.21691E-01      0.98189E-02       0.10449           10.641
   PROPANE             0.10354          0.88578E-01       0.20788           2.3469
   N-BUTANE            0.97837E-01      0.10367           0.57185E-01      0.55163
   1-BUTENE            0.13697          0.14384           0.89091E-01      0.61939
   1,3-BUTA            0.61963          0.65236           0.39141          0.60000




                                           – 21 –
    Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course


                            Exercise A.2 Solution using ASPEN.PLUS




Several variables are tabulated as a function of the purge/recycle ratio:


                                                                       Purge        Purge
        Purge/Recycle       PROD         Recycle           Purge       Mole         Mole
            Ratio         flow rate,    flow rate,       flow rate,   fraction     fraction
                          lbmole/h      lbmole/h         lbmole/h        Ar          CH4
              0.1            39.2         191.0            19.1        0.028        0.052
              0.08           40.75        209.3            16.7        0.033        0.060
              0.06           42.4         233.9            14.0        0.040        0.074
              0.04           44.3         273.5            10.9        0.053        0.093
              0.02           45.8         405.6             8.1        0.072        0.133

In all cases, the mole fraction of Ar and CH4 in the purge are significantly greater than in the feed.
As the purge/recycle ratio is decreased, the vapor effluent from the flash vessel becomes richer in
the inert species and less H2 and N2 are lost in the purge stream. However, this is accompanied
by a significant increase in the recycle rate and the cost of recirculation, as well as reactor
volume. Note that the EXAM4-3.BKP file on this CD-ROM can be used to reproduce these
results. Although not implemented in this file, the purge/recycle ratio can be adjusted
parametrically by varying the fraction of stream S5 purged in a sensitivity analysis, which is one
of the model analysis tools in ASPEN PLUS. The capital and operating costs can be estimated
and a profitability measure optimized as a function of the purge/recycle ratio.



                                                – 22 –
Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course


                        Exercise A.3 Solution using ASPEN.PLUS

        ASPEN PLUS Flowsheet - simulation results can be reproduced using the
                         file EXER3-7.BKP on the CD-ROM.

                                                                V1




                                                     F1


                                                 FLASH2



                                                V2        L1




                                                     F2
                                 FEED

                                                 FLASH2

                                           V3

                                                           L2




                                                     F3


                                                 FLASH2



                                                V4        L3




                                                     F4


                                                 FLASH2



                                                                L4




    ASPEN PLUS Program

       IN-UNITS ENG
       DEF-STREAMS CONVEN ALL
       DESCRIPTION "General Simulation with English Units :
               F, psi, lb/hr, lbmol/hr, Btu/hr, cuft/hr.
               Property Method: None   Flow basis for input: Mole
               Stream report composition: Mole flow "
       DATABANKS PURE10 / AQUEOUS / SOLIDS / INORGANIC / &
               NOASPENPCD
       PROP-SOURCES PURE10 / AQUEOUS / SOLIDS / INORGANIC
       COMPONENTS
           NITROGEN N2 NITROGEN /
           CO2 CO2 CO2 /
           H2S H2S H2S /
           METHANE CH4 METHANE /
           ETHANE C2H6 ETHANE /
           PROPANE C3H8 PROPANE /
           ISOBU-01 C4H10-2 ISOBU-01 /
                                            – 23 –
Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

           N-BUT-01 C4H10-1 N-BUT-01 /
           2-MET-01 C5H12-2 2-MET-01 /
           N-PEN-01 C5H12-1 N-PEN-01 /
           N-HEX-01 C6H14-1 N-HEX-01 /
           N-HEP-01 C7H16-1 N-HEP-01 /
           N-OCT-01 C8H18-1 N-OCT-01 /
           N-NON-01 C9H20-1 N-NON-01 /
           N-DEC-01 C10H22-1 N-DEC-01 /
           N-DOD-01 C12H26 N-DOD-01
       FLOWSHEET
           BLOCK F1 IN=V2 OUT=V1 L1
           BLOCK F2 IN=FEED L1 V3 OUT=V2 L2
           BLOCK F3 IN=L2 V4 OUT=V3 L3
           BLOCK F4 IN=L3 OUT=V4 L4
       PROPERTIES RK-SOAVE
       PROP-DATA RKSKIJ-1
           IN-UNITS ENG
           PROP-LIST RKSKIJ
           BPVAL NITROGEN CO2 -.0315000000
           BPVAL NITROGEN H2S .1696000000
           BPVAL NITROGEN METHANE .0278000000
           BPVAL NITROGEN ETHANE .0407000000
           BPVAL NITROGEN PROPANE .0763000000
           BPVAL NITROGEN ISOBU-01 .0944000000
           BPVAL NITROGEN N-BUT-01 .0700000000
           BPVAL NITROGEN 2-MET-01 .0867000000
           BPVAL NITROGEN N-PEN-01 .0878000000
           BPVAL NITROGEN N-HEX-01 .1496000000
           BPVAL NITROGEN N-HEP-01 .1422000000
           BPVAL NITROGEN N-OCT-01 -.4000000000
           BPVAL CO2 H2S .0989000000
           BPVAL CO2 METHANE .0933000000
           BPVAL CO2 ETHANE .1363000000
           BPVAL CO2 PROPANE .1289000000
           BPVAL CO2 ISOBU-01 .1285000000
           BPVAL CO2 N-BUT-01 .1430000000
           BPVAL CO2 2-MET-01 .1307000000
           BPVAL CO2 N-PEN-01 .1311000000
           BPVAL CO2 N-HEX-01 .1178000000
           BPVAL CO2 N-HEP-01 .1100000000
           BPVAL CO2 NITROGEN -.0315000000
           BPVAL H2S CO2 .0989000000
           BPVAL H2S ETHANE .0852000000
           BPVAL H2S PROPANE .0885000000
           BPVAL H2S ISOBU-01 .0511000000
           BPVAL H2S N-PEN-01 .0689000000
           BPVAL H2S NITROGEN .1696000000
           BPVAL METHANE CO2 .0933000000
           BPVAL METHANE ETHANE -7.8000000E-3
           BPVAL METHANE PROPANE 9.00000000E-3
           BPVAL METHANE ISOBU-01 .0241000000
           BPVAL METHANE N-BUT-01 5.60000000E-3
           BPVAL METHANE 2-MET-01 -7.8000000E-3
           BPVAL METHANE N-PEN-01 .0190000000
           BPVAL METHANE N-HEX-01 .0374000000
           BPVAL METHANE N-HEP-01 .0307000000
           BPVAL METHANE N-OCT-01 .0448000000
           BPVAL METHANE NITROGEN .0278000000
           BPVAL METHANE N-NON-01 .0448000000
           BPVAL ETHANE CO2 .1363000000
           BPVAL ETHANE H2S .0852000000
           BPVAL ETHANE METHANE -7.8000000E-3
           BPVAL ETHANE PROPANE -2.2000000E-3
           BPVAL ETHANE ISOBU-01 -.0100000000
           BPVAL ETHANE N-BUT-01 6.70000000E-3
                                           – 24 –
Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

            BPVAL   ETHANE N-PEN-01 5.60000000E-3
            BPVAL   ETHANE N-HEX-01 -.0156000000
            BPVAL   ETHANE N-HEP-01 4.10000000E-3
            BPVAL   ETHANE N-OCT-01 .0170000000
            BPVAL   ETHANE NITROGEN .0407000000
            BPVAL   PROPANE CO2 .1289000000
            BPVAL   PROPANE H2S .0885000000
            BPVAL   PROPANE METHANE 9.00000000E-3
            BPVAL   PROPANE ETHANE -2.2000000E-3
            BPVAL   PROPANE ISOBU-01 -.0100000000
            BPVAL   PROPANE N-BUT-01 0.0
            BPVAL   PROPANE 2-MET-01 7.80000000E-3
            BPVAL   PROPANE N-PEN-01 .0233000000
            BPVAL   PROPANE N-HEX-01 -2.2000000E-3
            BPVAL   PROPANE N-HEP-01 4.40000000E-3
            BPVAL   PROPANE NITROGEN .0763000000
            BPVAL   ISOBU-01 CO2 .1285000000
            BPVAL   ISOBU-01 H2S .0511000000
            BPVAL   ISOBU-01 METHANE .0241000000
            BPVAL   ISOBU-01 ETHANE -.0100000000
            BPVAL   ISOBU-01 PROPANE -.0100000000
            BPVAL   ISOBU-01 N-BUT-01 1.10000000E-3
            BPVAL   ISOBU-01 NITROGEN .0944000000
            BPVAL   N-BUT-01 CO2 .1430000000
            BPVAL   N-BUT-01 METHANE 5.60000000E-3
            BPVAL   N-BUT-01 ETHANE 6.70000000E-3
            BPVAL   N-BUT-01 PROPANE 0.0
            BPVAL   N-BUT-01 ISOBU-01 1.10000000E-3
            BPVAL   N-BUT-01 N-PEN-01 .0204000000
            BPVAL   N-BUT-01 N-HEX-01 -.0111000000
            BPVAL   N-BUT-01 N-HEP-01 -4.0000000E-4
            BPVAL   N-BUT-01 NITROGEN .0700000000
            BPVAL   2-MET-01 CO2 .1307000000
            BPVAL   2-MET-01 METHANE -7.8000000E-3
            BPVAL   2-MET-01 PROPANE 7.80000000E-3
            BPVAL   2-MET-01 N-PEN-01 0.0
            BPVAL   2-MET-01 NITROGEN .0867000000
            BPVAL   N-PEN-01 CO2 .1311000000
            BPVAL   N-PEN-01 H2S .0689000000
            BPVAL   N-PEN-01 METHANE .0190000000
            BPVAL   N-PEN-01 ETHANE 5.60000000E-3
            BPVAL   N-PEN-01 PROPANE .0233000000
            BPVAL   N-PEN-01 N-BUT-01 .0204000000
            BPVAL   N-PEN-01 2-MET-01 0.0
            BPVAL   N-PEN-01 N-HEP-01 1.90000000E-3
            BPVAL   N-PEN-01 N-OCT-01 -2.2000000E-3
            BPVAL   N-PEN-01 NITROGEN .0878000000
            BPVAL   N-HEX-01 CO2 .1178000000
            BPVAL   N-HEX-01 METHANE .0374000000
            BPVAL   N-HEX-01 ETHANE -.0156000000
            BPVAL   N-HEX-01 PROPANE -2.2000000E-3
            BPVAL   N-HEX-01 N-BUT-01 -.0111000000
            BPVAL   N-HEX-01 N-HEP-01 -1.1000000E-3
            BPVAL   N-HEX-01 NITROGEN .1496000000
            BPVAL   N-HEP-01 CO2 .1100000000
            BPVAL   N-HEP-01 METHANE .0307000000
            BPVAL   N-HEP-01 ETHANE 4.10000000E-3
            BPVAL   N-HEP-01 PROPANE 4.40000000E-3
            BPVAL   N-HEP-01 N-BUT-01 -4.0000000E-4
            BPVAL   N-HEP-01 N-PEN-01 1.90000000E-3
            BPVAL   N-HEP-01 N-HEX-01 -1.1000000E-3
            BPVAL   N-HEP-01 NITROGEN .1422000000
            BPVAL   N-OCT-01 METHANE .0448000000
            BPVAL   N-OCT-01 ETHANE .0170000000
            BPVAL   N-OCT-01 N-PEN-01 -2.2000000E-3
                                           – 25 –
  Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

             BPVAL N-OCT-01 NITROGEN -.4000000000
             BPVAL N-NON-01 METHANE .0448000000
         STREAM FEED
             SUBSTREAM MIXED TEMP=120. PRES=284.7
             MOLE-FLOW NITROGEN 358.2 / CO2 4965.6 / H2S 339.4 / &
                 METHANE 2995.5 / ETHANE 2395.5 / PROPANE 2291. / &
                 ISOBU-01 604.1 / N-BUT-01 1539.9 / 2-MET-01 790.4 / &
                 N-PEN-01 1129.9 / N-HEX-01 1764.7 / N-HEP-01 2606.7 / &
                 N-OCT-01 1844.5 / N-NON-01 1669. / N-DEC-01 831.7 / &
                 N-DOD-01 1214.5
         BLOCK F1 FLASH2
             PARAM TEMP=100. PRES=814.7
         BLOCK F2 FLASH2
             PARAM TEMP=120. PRES=284.7
         BLOCK F3 FLASH2
             PARAM TEMP=96. PRES=63.7
         BLOCK F4 FLASH2
             PARAM TEMP=85. PRES=27.7


      Calculation Sequence

         SEQUENCE USED WAS:
             $OLVER01 F2 F1 F3 F4
             (RETURN $OLVER01)

      Stream Variables

FEED L1 L2 L3 L4
----------------
STREAM ID                  FEED         L1            L2         L3           L4
FROM :                     ----         F1            F2         F3           F4
TO   :                     F2           F2            F3         F4           ----

SUBSTREAM: MIXED
PHASE:                     MIXED        LIQUID        LIQUID     LIQUID       LIQUID
COMPONENTS: LBMOL/HR
  NITROGEN                358.2000       7.2105     22.8707       0.4965    1.7507-02
  CO2                    4965.6000     332.2386   1913.4766     309.4625      74.1176
  H2S                     339.4000      36.5041    290.1682     110.4444      52.4278
  METHANE                2995.5000     116.1405    445.3504      24.4871       2.1453
  ETHANE                 2395.5000     237.2793   1510.5860     404.8408     145.5180
  PROPANE                2291.0000     275.7346   2608.0792    1543.6508    1020.4873
  ISOBU-01                604.1000      53.7814    701.2211     556.9299     461.9468
  N-BUT-01               1539.9000     114.5864   1742.7375    1472.3644    1284.4581
  2-MET-01                790.4000      37.2868    845.8587     785.7948     741.2558
  N-PEN-01               1129.9000      44.8785   1191.6967    1125.5810    1077.0711
  N-HEX-01               1764.7000      35.8039   1803.2644    1769.6980    1745.8170
  N-HEP-01               2606.7000      24.9910   2628.7094    2611.1753    2599.6604
  N-OCT-01               1844.5000       7.6824   1850.3056    1846.0705    1843.5053
  N-NON-01               1669.0000       2.9719   1670.9576    1669.5788    1668.8073
  N-DEC-01                831.7000       0.6467    832.0568     831.8028     831.6730
  N-DOD-01               1214.5000       0.1750   1214.5759    1214.5223    1214.4983
TOTAL FLOW:
  LBMOL/HR               2.7341+04   1327.9123    2.1272+04    1.6277+04    1.4763+04
  LB/HR                  1.8877+06   5.9910+04    1.7211+06    1.5183+06    1.4479+06
  CUFT/HR                2.1582+05   1766.0410    4.4062+04    3.7357+04    3.4976+04
STATE VARIABLES:
  TEMP    F               120.0000     100.0000    120.0000      96.0000      85.0000
  PRES    PSI             284.7000     814.7000    284.7000      63.7000      27.7000
  VFRAC                     0.3191       0.0         0.0          0.0          0.0
  LFRAC                     0.6809       1.0000      1.0000       1.0000       1.0000
  SFRAC                     0.0          0.0         0.0          0.0          0.0
ENTHALPY:

                                             – 26 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

   BTU/LBMOL            -9.0812+04 -8.1807+04 -9.0021+04 -9.2361+04 -9.5063+04
   BTU/LB               -1315.3024 -1813.2724 -1112.5881 -990.1566 -969.2754
   BTU/HR               -2.4829+09 -1.0863+08 -1.9149+09 -1.5033+09 -1.4035+09
 ENTROPY:
   BTU/LBMOL-R            -102.5609     -59.6746   -131.6561     -160.4215   -171.0890
   BTU/LB-R                 -1.4854      -1.3227     -1.6271       -1.7198     -1.7444
 DENSITY:
   LBMOL/CUFT                0.1266       0.7519        0.4827      0.4357      0.4221
   LB/CUFT                   8.7464      33.9231       39.0618     40.6431     41.3986
 AVG MW                     69.0427      45.1156       80.9113     93.2790     98.0761

V1 V2 V3 V4
 -----------
 STREAM ID                  V1           V2            V3          V4
 FROM :                     F1           F2            F3          F4
 TO   :                     ----         F1            F2          F3

 SUBSTREAM: MIXED
 PHASE:                  VAPOR      VAPOR      VAPOR      VAPOR
 COMPONENTS: LBMOL/HR
   NITROGEN             358.1823   365.3929    22.8531     0.4790
   CO2                 4891.4779 5223.7206 1839.3587     235.3453
   H2S                  286.9707   323.4754   237.7394    58.0165
   METHANE             2993.3523 3109.4945    443.2043    22.3418
   ETHANE              2249.9775 2487.2597 1365.0663     259.3229
   PROPANE             1270.4888 1546.2281 1587.5726     523.1608
   ISOBU-01             142.1566   195.9392   239.2790    94.9836
   N-BUT-01             255.4380   370.0255   458.2766   187.9059
   2-MET-01              49.1434    86.4305   104.6024    44.5389
   N-PEN-01              52.8281    97.7067   114.6249    48.5097
   N-HEX-01              18.8826    54.6866    57.4472    23.8809
   N-HEP-01               7.0393    32.0304    29.0488    11.5148
   N-OCT-01               0.9946     8.6771     6.8003     2.5651
   N-NON-01               0.1926     3.1645     2.1503     0.7715
   N-DEC-01            2.6929-02     0.6736     0.3837     0.1297
   N-DOD-01            1.6948-03     0.1767 7.7688-02 2.4046-02
 TOTAL FLOW:
   LBMOL/HR            1.2577+04 1.3905+04 6508.4859 1513.4910
   LB/HR               4.3973+05 4.9964+05 2.7320+05 7.0356+04
   CUFT/HR             6.5192+04 2.7614+05 5.8513+05 3.1096+05
 STATE VARIABLES:
   TEMP    F            100.0000   120.0000    96.0000    85.0000
   PRES    PSI          814.7000   284.7000    63.7000    27.7000
   VFRAC                  1.0000     1.0000     1.0000     1.0000
   LFRAC                  0.0        0.0        0.0        0.0
   SFRAC                  0.0        0.0        0.0        0.0
 ENTHALPY:
   BTU/LBMOL          -8.8006+04 -8.5897+04 -7.7953+04 -6.5079+04
   BTU/LB             -2517.1525 -2390.5307 -1857.0901 -1399.9728
   BTU/HR             -1.1069+09 -1.1944+09 -5.0736+08 -9.8497+07
 ENTROPY:
   BTU/LBMOL-R          -27.9154   -26.5798   -39.3918   -53.5736
   BTU/LB-R              -0.7984    -0.7397    -0.9384    -1.1524
 DENSITY:
   LBMOL/CUFT             0.1929 5.0355-02 1.1123-02 4.8671-03
   LB/CUFT                6.7451     1.8093     0.4669     0.2262
 AVG MW                  34.9626    35.9322    41.9759    46.4861




                                              – 27 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                                         Thermodynamics

HYSYS.Plant

        The materials that support a course in thermodynamics have not yet been class-tested.
However, it is recommended that thermodynamics instructors consider allotting three hours of
computer laboratory time for the exercises. A self-paced approach using the multimedia allows
the students to bring themselves “up-to-speed” on the selection of property prediction methods,
and their applications in VLE calculations, and to perform chemical equilibrium calculations.
The following sequence of modules is recommended:


Session 1:   Under HYSYS – Physical Property Estimation – Package selection, students are
             provided with a guide to the correct selection of physical property methods, and
             their impact on VLE calculations. It is recommended that students be assigned an
             exercise that allows them to test the recommendations, which are implemented as
             decision-trees (e.g., Exercise B.2).




Session 2:   Under HYSYS – Separators, the main menu refers to item 1, Flash. Students
             should review the background material on K-value computations for VLE
             computations and see the video of an industrial flash vessel. They will also find
             helpful the section on the use of the HYSYS Separator, modeling the flash unit.




                                              – 28 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

Session 3:   Under HYSYS – Chemical Reactors, the main menu refers to item 3, Setting up
             Reactors. Students can review the modules on the Equilibrium Reactor, for
             calculations involving the mass-action equations, and on the Gibbs Reactor for
             calculations involving the direct minimization of the Gibbs free energy.




To reinforce their acquired capabilities, students should be assigned a homework exercise. Three
typical exercises are provided:
       Exercise B.1 Refrigerator Design Problem
       Exercise B.2 VLLE Problem
       Exercise B.4 Chemical Equilibrium Problem




                                              – 29 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

ASPEN PLUS

        The materials that support a course in thermodynamics have not yet been class-tested.
However, it is recommended that thermodynamics instructors consider allotting four hours of
computer laboratory time for the exercises. A self-paced approach using the multimedia allows
the students to bring themselves “up-to-speed” on the use of a process simulator to carry out the
energy balances in a refrigerator, to perform VLE calculations, and to perform chemical
equilibrium calculations. The following sequence of modules is recommended:


Session 1:   Under ASPEN – Pumps & Compressors, the main menu refers to item 2,
             Compressors and Expanders. Students should see the video of an industrial
             compressor and review the module on ASPEN PLUS (COMPR, MCOMPR). Then,
             under ASPEN PLUS – Heat Exchangers, the main menu refers to item 2, Heat
             Requirement Models. Students should review this module. For the refrigerator
             process, the multimedia doesn’t have a module on valves. Students can use the
             ASPEN PLUS VALVE subroutine with little preparation.




Session 2:   Under ASPEN – Separators, the main menu refers to item 3, Phase Equil. and
             Flash. Students should see the video of an industrial flash vessel and review the
             two modules on FLASH 2 and FLASH 3.




             In addition, under Physical Property Estimation, the main menu refers to item 3,
             Property Estimation. Students can review the basis for VLE calculations in module
             on Phase Equilibria, methods for using ASPEN PLUS to draw equilibrium

                                              – 30 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

             diagrams in the modules on Binary Phase Diagrams and Phase Envelopes, and
             methods for regressing VLE data in the module Property Data Regression.




Session 3:   Under ASPEN – Reactors, the main menu refers to item 3, Equilibrium Reactors.
             Students can review the modules on the Equilibrium Reactor (REQUIL), for
             calculations involving the mass-action equations, and on the Gibbs Reactor
             (RGIBBS) for calculations involving the direct minimization of the Gibbs free
             energy.




To reinforce their acquired capabilities, students should be assigned a homework exercise. Five
typical exercises are provided:
       Exercise B.1 Refrigerator Design Problem
       Exercise B.2 VLLE Problem
       Exercise B.3 VLE Data Regression Problem
       Exercise B.4 Chemical Equilibrium Problem
       Exercise B.5 Selection of an Environmentally-friendly Refrigerant




                                              – 31 –
     Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                            Exercise B.1 Refrigerator Design Problem

        This is extension of Example 6.2 in Seider, Seader, and Lewin (1999), which involves a
refrigeration loop:




In this problem, it is desired to:

a.     simulate the refrigeration cycle assuming that the compressor has an isentropic efficiency of
       0.9. For the evaporator and condenser, do not simulate the heat exchangers. Instead, use
       models that compute the “heat required” to be absorbed by the evaporating propane and to
       be removed from the condensing propane. Use the Soave-Redlich-Kwong equation and a
       propane flow rate of 5,400 lb/hr. Set the pressure levels as indicated above, but recognize
       that the temperatures may differ due to the VLE model.

b.     calculate the lost work and the thermodynamic efficiency for the refrigeration cycle.


                    HYSYS.Plant Solution                 ASPEN PLUS Solution




                                                – 32 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course


                                  Exercise B.2 VLLE Problem


        An equimolar stream of benzene, toluene, and water at 150 kgmole/hr, 100°C, and 7 bar
enters a flash vessel. It is expanded to 0.5 bar and cooled to 60°C. Use a process simulator with
the UNIFAC method, having liquid-liquid interaction coefficients, for estimating liquid-phase
activity coefficients to compute the flow rates and compositions of the three product streams.
Also, determine the heat added or removed. If using ASPEN PLUS, the FLASH3 subroutine and
the UNIF-LL property option are appropriate. If using HYSYS.Plant, use the 3-phase Separator,
and select the appropriate physical property method as guided by the multimedia.



                  HYSYS.Plant Solution                 ASPEN PLUS Solution




                                              – 33 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                         Exercise B.3 VLE Data Regression Problem

        The following vapor-liquid equilibrium data for ethanol and benzene at 1 atm have been
taken from the Gmehling and Onken data bank:
                                    x            y            T,°C
                                            0             0          80.13
                                        0.025        0.1303          76.29
                                         0.05        0.2117          73.77
                                        0.075        0.2654          72.09
                                           0.1       0.3029          70.94
                                        0.125        0.3304          70.12
                                         0.15        0.3514          69.53
                                        0.175        0.3681          69.08
                                           0.2       0.3818          68.75
                                        0.225        0.3933          68.49
                                         0.25        0.4033          68.28
                                        0.275        0.4121          68.12
                                           0.3       0.4201          68.00
                                        0.325        0.4274          67.90
                                         0.35        0.4343          67.82
                                        0.375        0.4408          67.76
                                           0.4       0.4472          67.72
                                        0.425        0.4534          67.69
                                         0.45        0.4596          67.68
                                        0.475        0.4659          67.68
                                           0.5       0.4724          67.69
                                        0.525        0.4791          67.72
                                         0.55        0.4860          67.77
                                        0.575        0.4935          67.82
                                           0.6       0.5015          67.90
                                        0.625        0.5101          68.00
                                         0.65        0.5195          68.13
                                        0.675        0.5298          68.28
                                           0.7       0.5413          68.47
                                        0.725        0.5542          68.69
                                         0.75        0.5689          68.97
                                        0.775        0.5856          69.30
                                           0.8       0.6049          69.70
                                        0.825        0.6273          70.19
                                         0.85        0.6539          70.78
                                        0.875        0.6855          71.49
                                           0.9       0.7238          72.36
                                        0.925        0.7707          73.41
                                         0.95        0.8293          74.72
                                        0.975        0.9036          76.32
                                            1             1          78.31



                                                 – 34 –
     Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

For the design of a distillation column to produce nearly pure ethanol, it is desired to obtain a
close match between the computed VLE and the Gmehling and Onken data.

a.     Use the binary interaction coefficients for the UNIQUAC equation for liquid-phase
       interaction coefficients, in the data bank of a process simulator, to prepare T-x-y and x-y
       diagrams.

b.     Use data points having ethanol mole fractions above its azeotropic mole fraction with a
       regression program in a process simulator. Determine interaction coefficients that give
       better agreement with the Gmehling and Onken data at high ethanol concentrations. Show
       how the T-x-y and x-y diagrams compare using these data points.

                                      ASPEN PLUS Solution


                           Exercise B.4 Chemical Equilibrium Problem


       An equimolar stream of ammonia, oxygen, nitrogen oxide (NO), nitrogen dioxide (NO2),
and water at 100 lbmole/hr, 300°F, and 1 atm enters a tank reactor. Determine the flow rate and
composition of the reactor effluent, assuming that chemical equilibrium is attained. Use a
process simulator, assuming that the ideal gas law applies.

a.     Determine the number of independent reactions. Then, determine a set of independent
       reactions.

b.     Obtain chemical equilibrium by solving the mass-action equations (using K-values). If
       using ASPEN PLUS, the REQUIL subroutine is appropriate.

c.     Obtain chemical equilibrium by minimizing the Gibbs free energy. Note that it is not
       necessary to specify an independent reaction set. If using ASPEN PLUS, the RGIBBS
       subroutine is appropriate.


                                      ASPEN PLUS Solution


                Exercise B.5 Selection of an Environmentally-friendly Refrigerant

        It is desired to find a refrigerant that removes heat at -20°C and rejects heat at 32°C.
Desirable refrigerants should have Ps{-20°C} > 1.4 bar, Ps{32°C} < 14 bar,
 ∆Hv{-20°C} > 18.4 kJ/mol, and cpl{6°C} > 18.4 kJ/mol. For the candidate groups, CH3, CH, F,
and S, formulate a mixed-integer nonlinear program and use GAMS to solve it. Hint: maximize
the objective function, ∆Hv{-20°C}.




                                                – 35 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                             Exercise B.1 Solution using HYSYS.Plant

                                  Refrigerator Design Problem Solution


a. Solution using HYSYS.Plant. This solution can be reproduced using the file, REFRIG.HSC.




     HYSYS.Plant Report.

Fluid Package: Basis-1                Property Package: SRK

Material Stream: S-1                  Overall                         Vapour Phase          Liquid Phase
Vapour / Phase Fraction                                           1                     1                0
Temperature: (F)                                          8.44E-02              8.44E-02         8.44E-02
Pressure: (psia)                                              38.37                 38.37            38.37
Molar Flow (lbmole/hr)                                        122.5                 122.5                0
Mass Flow (lb/hr)                                             5400                   5400                0
Liquid Volume Flow (barrel/day)                               729.8                 729.8                0
Molar Enthalpy (Btu/lbmole)                              -4.61E+04             -4.61E+04        -5.38E+04
Molar Entropy (Btu/lbmole-F)                                  33.92                 33.92            17.21
Heat Flow (Btu/hr)                                       -5.65E+06             -5.65E+06                 0

Material Stream: S-2                  Overall                         Vapour Phase
Vapour / Phase Fraction                                           1                     1
Temperature: (F)                                              118.7                 118.7
Pressure: (psia)                                                187                   187
Molar Flow (lbmole/hr)                                        122.5                 122.5
Mass Flow (lb/hr)                                              5400                  5400
Liquid Volume Flow (barrel/day)                               729.8                 729.8
Molar Enthalpy (Btu/lbmole)                              -4.45E+04             -4.45E+04
Molar Entropy (Btu/lbmole-F)                                  34.23                 34.23
Heat Flow (Btu/hr)                                       -5.45E+06             -5.45E+06

Material Stream: S-3                  Overall                         Liquid Phase          Vapour Phase
Vapour / Phase Fraction                                          0                     1               0
                                                – 36 –
     Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

Temperature: (F)                                                  97.52                 97.52        97.52
Pressure: (psia)                                                    185                   185          185
Molar Flow (lbmole/hr)                                            122.5                 122.5            0
Mass Flow (lb/hr)                                                  5400                  5400            0
Liquid Volume Flow (barrel/day)                                   729.8                 729.8            0
Molar Enthalpy (Btu/lbmole)                                  -5.10E+04             -5.10E+04    -4.50E+04
Molar Entropy (Btu/lbmole-F)                                      22.65                 22.65        33.46
Heat Flow (Btu/hr)                                           -6.25E+06             -6.25E+06             0

Material Stream: S-4                     Overall                        Vapour Phase         Liquid Phase
Vapour / Phase Fraction                                          0.3596              0.3596          0.6404
Temperature: (F)                                                  2.193               2.193           2.193
Pressure: (psia)                                                     40                   40             40
Molar Flow (lbmole/hr)                                            122.5               44.03           78.42
Mass Flow (lb/hr)                                                  5400                1942            3458
Liquid Volume Flow (barrel/day)                                   729.8               262.4           467.3
Molar Enthalpy (Btu/lbmole)                                  -5.10E+04           -4.61E+04       -5.38E+04
Molar Entropy (Btu/lbmole-F)                                      23.29                 33.9          17.33
Heat Flow (Btu/hr)                                           -6.25E+06           -2.03E+06       -4.22E+06

Cooler: E-100
Pressure Drop: 2.000 psi                 Duty: 7.920e+005 Btu/hr          Volume: 3.531 ft3
Heater: E-101
PARAMETERS
Pressure Drop: 1.630 psi                 Duty: 5.970e+005 Btu/hr          Volume: 3.531 ft3
Compressor: K-100
Duty: 1.9503e+05 Btu/hr                  Adiabatic Eff.: 89.00         PolyTropic Eff.: 90.21
Speed:                                   Adiabatic Head: 2.501e+004 ft Polytropic Head: 2.535e+004 ft
Polytropic Exp. 1.063                    Isentropic Exp. 1.044         Poly Head Factor 1.015
User Variables
Valve: VLV-100
Pressure Drop: 145.0 psi

b.       Lost work (see Eq. (6.23), Seider, Seader, Lewin (1999)):

                                  T0       
                 LW = Win + 1 −             QEvap
                             T             
                                Evaporator 

                    = 70 kW + (1 – 537/470)×176.3 kW = 70 – 25.1 = 44.9 kW

       Thermodynamic efficiency (see Eq. (6.27), Seider, Seader, Lewin (1999)):

                                  main goal         − 25.1
                η ( −) goal =                  =               = 0.359
                                main goal − LW   − 25.1 − 44.9

       See SSL for calculations of the lost work in each process unit. Also, see Example 6.3 in
       which the valve is replaced by a power recovery turbine.


                                                    – 37 –
Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                        Exercise B.1 Solution using ASPEN.PLUS


a. Solution using ASPEN PLUS. This solution can be reproduced using the file,
   REFRIG.BKP.

                            S1                    C1




                                                       S2


                           EVAP1
                                                                     COND1




                                             V1

                            S4                         S3




  ASPEN PLUS Program

      TITLE 'PROPANE REFRIGERATION LOOP'
      IN-UNITS ENG
      DEF-STREAMS CONVEN ALL
      DESCRIPTION "
          General Simulation with English Units :
          F, psi, lb/hr, lbmol/hr, Btu/hr, cuft/hr.
          Property Method: None
          Flow basis for input: Mole
          Stream report composition: Mole flow
          "
      DATABANKS PURE11 / AQUEOUS / SOLIDS / INORGANIC / &
              NOASPENPCD
      PROP-SOURCES PURE11 / AQUEOUS / SOLIDS / INORGANIC
      COMPONENTS
          PROPANE C3H8
      FLOWSHEET
          BLOCK EVAP1 IN=S4 OUT=S1
          BLOCK COND1 IN=S2 OUT=S3
          BLOCK C1 IN=S1 OUT=S2
          BLOCK V1 IN=S3 OUT=S4
      PROPERTIES RK-SOAVE
      STREAM S3
          SUBSTREAM MIXED PRES=185. VFRAC=0. MASS-FLOW=5400.
          MOLE-FRAC PROPANE 1.
      BLOCK COND1 HEATER
          PARAM PRES=185. VFRAC=0.
      BLOCK EVAP1 HEATER
          PARAM PRES=38.37 VFRAC=1.
      BLOCK C1 COMPR
          PARAM TYPE=ISENTROPIC PRES=187. SEFF=0.9
      BLOCK V1 VALVE
          PARAM P-OUT=40.
      EO-CONV-OPTI
      STREAM-REPOR MOLEFLOW

  Stream Variables

      S1 S2 S3 S4
      -----------

                                           – 38 –
  Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course


         STREAM ID                   S1             S2        S3           S4
         FROM :                      EVAP1          C1        COND1        V1
         TO   :                      C1             COND1     V1           EVAP1

         MAX CONV. ERROR:         0.0        0.0    -8.8208-08     0.0
         SUBSTREAM: MIXED
         PHASE:                  VAPOR      VAPOR      LIQUID     MIXED
         COMPONENTS: LBMOL/HR
           PROPANE              122.4586   122.4586   122.4586   122.4586
         TOTAL FLOW:
           LBMOL/HR             122.4586   122.4586   122.4586   122.4586
           LB/HR               5400.0000 5400.0000 5400.0000 5400.0000
           CUFT/HR             1.4709+04 3328.3100    182.1782 5122.5994
         STATE VARIABLES:
           TEMP    F              0.1348   120.1738    97.5639     2.2450
           PRES    PSI           38.3700   187.0000   185.0000    40.0000
           VFRAC                  1.0000     1.0000     0.0        0.3551
           LFRAC                  0.0        0.0        1.0000     0.6449
           SFRAC                  0.0        0.0        0.0        0.0
         ENTHALPY:
           BTU/LBMOL          -4.6438+04 -4.4857+04 -5.1349+04 -5.1349+04
           BTU/LB             -1053.0957 -1017.2552 -1164.4737 -1164.4737
           BTU/HR             -5.6867+06 -5.4932+06 -6.2882+06 -6.2882+06
         ENTROPY:
           BTU/LBMOL-R          -69.0042   -68.7299   -80.3461   -79.7139
           BTU/LB-R              -1.5648    -1.5586    -1.8221    -1.8077
         DENSITY:
           LBMOL/CUFT          8.3256-03 3.6793-02      0.6722 2.3906-02
           LB/CUFT                0.3671     1.6224    29.6413     1.0542
         AVG MW                  44.0965    44.0965    44.0965    44.0965


    Selected Process Unit Output
BLOCK: C1        MODEL: COMPR
-----------------------------
                          ***      RESULTS    ***

  INDICATED HORSEPOWER REQUIREMENT HP                              76.0637
  BRAKE      HORSEPOWER REQUIREMENT HP                             76.0637
  NET WORK REQUIRED                  HP                            76.0637
  ISENTROPIC HORSEPOWER REQUIREMENT HP                             68.4573
  CALCULATED OUTLET TEMP F                                        120.174
  ISENTROPIC TEMPERATURE F                                        112.749
  EFFICIENCY (POLYTR/ISENTR) USED                                   0.90000
  HEAD DEVELOPED, FT-LBF/LB                                    25,101.0
  MECHANICAL EFFICIENCY USED                                        1.00000
  INLET HEAT CAPACITY RATIO                                         1.14081
  INLET VOLUMETRIC FLOW RATE , CUFT/HR                         14,708.6
  OUTLET VOLUMETRIC FLOW RATE, CUFT/HR                          3,328.31
  INLET COMPRESSIBILITY FACTOR                                      0.93399
  OUTLET COMPRESSIBILITY FACTOR                                     0.81679
  AV. ISENT. VOL. EXPONENT                                          1.04889
  AV. ISENT. TEMP EXPONENT                                          1.16052
  AV. ACTUAL VOL. EXPONENT                                          1.06586
  AV. ACTUAL TEMP EXPONENT                                          1.17158




                                             – 39 –
     Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

BLOCK: COND1     MODEL: HEATER
 ------------------------------

                                    *** RESULTS       ***
     OUTLET TEMPERATURE           F                                      97.564
     OUTLET PRESSURE              PSI                                    185.00
     HEAT DUTY                    BTU/HR                               -0.79498E+06


BLOCK: EVAP1     MODEL: HEATER
 ------------------------------

                                    *** RESULTS       ***
     OUTLET TEMPERATURE           F                                     0.13477
     OUTLET PRESSURE              PSI                                    38.370
     HEAT DUTY                    BTU/HR                                0.60144E+06

BLOCK: V1        MODEL: VALVE
 -----------------------------

                                    ***    RESULTS   ***

      VALVE PRESSURE DROP                 PSI                       145.000




b.                   Lost work (see Eq. (6.23), Seider, Seader, Lewin (1999)):

                                  T0           
                 LW = Win + 1 −                 QEvap
                             T                 
                                Evaporator     

                        = 70 kW + (1 – 537/470)×176.3 kW
                        = 70 – 25.1 = 44.9 kW

       Thermodynamic efficiency (see Eq. (6.27), Seider, Seader, Lewin (1999)):

                                  main goal
                η ( −) goal =
                                main goal − LW

                                   − 25.1
                           =                  = 0.359
                                − 25.1 − 44.9
       See SSL for calculations of the lost work in each process unit. Also, see Example 6.3 in
       which the valve is replaced by a power recovery turbine.




                                                     – 40 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                           Exercise B.2 Solution using HYSYS.Plant


Solution using 3-phase Separator in HYSYS.Plant. This solution can be reproduced using the
file, VLLE.HSC. Note that the physical properties are predicted using the NRTL activity
method, with UNIFAC-LL binary interaction coefficients, and assuming ideal vapor, as
recommended by both Eric Carlson and Bob Seader (Both indicate that the UNIFAC LL
estimation method is appropriate). The option to check for the possibility of two liquid phases
should be activated.




  NAME                                    FEED         VAP       LIQ1     LIQ2     SEP-DUTY
  Vapor Fraction                                  0            1        0        0
  Temperature [C]                               100          60       60       60
  Pressure [bar]                                  7          0.5      0.5      0.5
  Molar Flow [kgmol/h]                          150     106.929 35.82939 7.241573
  Mass Flow [kgl/h]                        9413.295     6158.99 3123.628 130.6777
  Liquid Volume Flow [m3/h]                  10.6248   6.918751    3.575073 0.13098
  Heat Flow [kcal/h]                       -2318423    -1321315      249418 -488242     758284.7
  Molar Enthalpy [kcal/kgmol]               -15456.2    -12356.9   6961.269   -67422
  Comp Molar Flow (Benzene) [kgmol/h]             50   38.05983    11.93832 1.85E-03
  Comp Molar Flow (Toluene) [kgmol/h]             50     26.2453   23.75324 1.47E-03
  Comp Molar Flow (Water) [kgmol/h]               50   42.62391    0.137836 7.238254


In the above table, values in blue are the process specifications, with the remaining values being
computed results. Note that the organic liquid product is LIQ1 and the aqueous liquid product is
LIQ2. To satisfy the energy balance, HYSYS.Plant computes 0.758 MMKcal/hr are added to the
flash vessel.




                                              – 41 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                           Exercise B.2 Solution using ASPEN.PLUS

Solution using the FLASH3 subroutine in ASPEN PLUS. This solution can be reproduced using
the file, VLLE.BKP.



                                               VAP




                                                       F1

                                   FEED                      LIQ1




                                                             LIQ2


ASPEN PLUS Program
   TITLE 'VLLE - BENZENE, TOLUENE, WATER'

   IN-UNITS MET VOLUME-FLOW='cum/hr' ENTHALPY-FLO='MMkcal/hr' &
           HEAT-TRANS-C='kcal/hr-sqm-K' PRESSURE=bar TEMPERATURE=C            &
           VOLUME=cum DELTA-T=C HEAD=meter MOLE-DENSITY='kmol/cum'            &
           MASS-DENSITY='kg/cum' MOLE-ENTHALP='kcal/mol' &
           MASS-ENTHALP='kcal/kg' HEAT=MMkcal MOLE-CONC='mol/l' &
           PDROP=bar
   DEF-STREAMS CONVEN ALL
   SIM-OPTIONS NPHASE=3
   DESCRIPTION "
       General Simulation with Metric Units :
       C, bar, kg/hr, kmol/hr, MMKcal/hr, cum/hr.
       Property Method: None
       Flow basis for input: Mole
       Stream report composition: Mole flow
   DATABANKS PURE10 / AQUEOUS / SOLIDS / INORGANIC / &
           NOASPENPCD
   PROP-SOURCES PURE10 / AQUEOUS / SOLIDS / INORGANIC
   COMPONENTS
       BENZENE C6H6 /
       TOLUENE C7H8 /
       WATER H2O
   FLOWSHEET
       BLOCK F1 IN=FEED OUT=VAP LIQ1 LIQ2
   PROPERTIES UNIF-LL
       PROPERTIES IDEAL / UNIFAC
   STREAM FEED
       SUBSTREAM MIXED TEMP=100. PRES=7. MOLE-FLOW=150.
       MOLE-FLOW BENZENE 50. / TOLUENE 50. / WATER 50.
   BLOCK F1 FLASH3
       PARAM TEMP=60. PRES=0.5
   STREAM-REPOR MOLEFLOW




                                              – 42 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

Stream Variables

    FEED LIQ1 LIQ2 VAP
    ------------------
    STREAM ID                    FEED         LIQ1        LIQ2         VAP
    FROM :                       ----         F1          F1           F1
    TO   :                       F1           ----        ----         ----
    SUBSTREAM: MIXED
    PHASE:                       LIQUID       LIQUID       LIQUID      VAPOR
    COMPONENTS: KMOL/HR
      BENZENE                    50.0000      14.3925    2.0372-03     35.6055
      TOLUENE                    50.0000      26.3020    1.3751-03     23.6966
      WATER                      50.0000       0.1748      10.4077     39.4175
    TOTAL FLOW:
      KMOL/HR                   150.0000      40.8693      10.4111     98.7197
      KG/HR                    9413.4720    3550.8775     187.7831   5674.8114
      CUM/HR                     11.7432       4.2699       0.1958   5408.5900
    STATE VARIABLES:
      TEMP    C                 100.0000      60.0000      60.0000     60.0000
      PRES    BAR                 7.0000       0.5000       0.5000      0.5000
      VFRAC                       0.0          0.0          0.0         1.0000
      LFRAC                       1.0000       1.0000       1.0000      0.0
      SFRAC                       0.0          0.0          0.0         0.0
    ENTHALPY:
      KCAL/MOL                  -15.5331       6.9826   -67.6121      -12.4644
      KCAL/KG                  -247.5143      80.3676 -3748.5570     -216.8315
      MMKCAL/HR                  -2.3300       0.2854    -0.7039       -1.2305
    ENTROPY:
      CAL/MOL-K                 -52.4388     -68.6094    -36.9819     -26.1730
      CAL/GM-K                   -0.8356      -0.7897     -2.0504      -0.4553
    DENSITY:
      KMOL/CUM                   12.7734       9.5715      53.1678   1.8252-02
      KG/CUM                    801.6136     831.6121     958.9778      1.0492
    AVG MW                       62.7565      86.8838      18.0368     57.4841

Note that the stream LIQ1 contains the organic phase and the stream LIQ2 contains the aqueous
                   phase.

Selected Process Unit Output

 BLOCK: F1        MODEL: FLASH3
 ------------------------------
   PROPERTY OPTION SET:   UNIF-LL          UNIFAC / REDLICH-KWONG

                           *** RESULTS          ***
   OUTLET TEMPERATURE    C                                             60.000
   OUTLET PRESSURE       BAR                                          0.50000
   HEAT DUTY             MMKCAL/HR                                    0.68096
   VAPOR FRACTION                                                     0.65813
   1ST LIQUID/TOTAL LIQUID                                            0.79698
   V-L1-L2 PHASE EQUILIBRIUM :

      COMP             F(I)        X1(I)    X2(I)     Y(I)            K1(I)       K2(I)
      BENZENE         0.333       0.352    0.196E-03 0.361            1.02       0.184E+04
      TOLUENE         0.333       0.644    0.132E-03 0.240           0.373       0.182E+04
      WATER           0.333       0.428E-02 1.00     0.399            93.4       0.399

         To satisfy the energy balance, 0.681 MMKcal/hr are added to the flash vessel.




                                                – 43 –
     Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                              Exercise B.3 Solution using ASPEN.PLUS


Solution obtained using ASPEN PLUS with the UNIQUAC method for estimating liquid-phase
activity coefficients. Results can be reproduced using the file, VLEREG.BKP.

a.                   From the ASPEN PLUS data banks, the following binary interaction
                     coefficients are used:

         aij = -0.464, aji = 0.4665, bij = 137.8, bji = -1,001.7

         Using these interaction coefficients, T-x-y and x-y graphs are prepared.




b.                   Using the data points for ethanol concentrations greater than or equal to 0.6
                     from the Gmehling and Onken data bank, the binary interaction coefficients
                     are adjusted by the ASPEN PLUS data regression program to:

                 aij = -0.464, aji = 0.4665, bij = 14.96, bji = -441.7

         In this case, just small changes are observed in the T-x-y and x-y diagrams.




                                                   – 44 –
     Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                             Exercise B.4 Solution using ASPEN PLUS

                               Chemical Equilibrium Problem Solution

a.                  NC = 5, R = rank of atom matrix = 3. Hence, NR = no. of independent
                    chemical reactions = NC – R = 5 – 3 = 2. For the atom matrix, see the solution
                    to part ‘c’.

b.                  Solution using the REQUIL subroutine in ASPEN PLUS. This solution can be
                    reproduced using the file, REQUIL.BKP.

                                                              VAP




                                                         R1

                                      FEED


                                                               LIQ


                    Note that when using the REQUIL subroutine, streams for both vapor and
                    liquid effluents must be defined, even when one doesn’t exist.

                    The two independent reactions are selected arbitrarily:

                                        NO + 1/2O2 = NO2
                                        4NH3 + 5O2 = 4NO + 6H2O

     ASPEN PLUS Program

         TITLE 'CHEMICAL EQUILIBRIUM - K-VALUES'
         IN-UNITS ENG
         DEF-STREAMS CONVEN ALL
         DATABANKS PURE10 / AQUEOUS / SOLIDS / INORGANIC / &
                 NOASPENPCD
         PROP-SOURCES PURE10 / AQUEOUS / SOLIDS / INORGANIC
         COMPONENTS
             AMMON-01 H3N /
             OXYGE-01 O2 /
             NITRI-01 NO /
             NITRO-01 NO2 /
             WATER H2O
         FLOWSHEET
             BLOCK R1 IN=FEED OUT=VAP LIQ
         PROPERTIES IDEAL
         STREAM FEED
             SUBSTREAM MIXED TEMP=300. PRES=1. <atm> MOLE-FLOW=100.
             MOLE-FRAC AMMON-01 0.2 / OXYGE-01 0.2 / NITRI-01 0.2 / &
                 NITRO-01 0.2 / WATER 0.2
         BLOCK R1 REQUIL
             PARAM NREAC=2 TEMP=300. PRES=1. <atm> NPHASE=2
             STOIC 1 NITRI-01 -1. * / OXYGE-01 -0.5 * / NITRO-01 1. &
                 *
             STOIC 2 AMMON-01 -4. * / OXYGE-01 -5. * / NITRI-01 4. &
                 * / WATER 6. *
             TAPP-SPEC 1 0.0 / 2 0.0
         STREAM-REPOR MOLEFLOW

                                                – 45 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

   Stream Variables

        FEED LIQ VAP
        ------------

        STREAM ID                   FEED        LIQ          VAP
        FROM :                      ----        R1           R1
        TO   :                      R1          ----         ----

        SUBSTREAM: MIXED
        PHASE:                  VAPOR           MISSING      VAPOR
        COMPONENTS: LBMOL/HR
          AMMON-01              20.0000           0.0         0.0
          OXYGE-01              20.0000           0.0      1.5913-06
          NITRI-01              20.0000           0.0        50.0042
          NITRO-01              20.0000           0.0        10.0027
          WATER                 20.0000           0.0        50.0042
        TOTAL FLOW:
          LBMOL/HR             100.0000           0.0       110.0111
          LB/HR               2861.1264           0.0      2861.4532
          CUFT/HR             5.5473+04           0.0      6.1027+04
        STATE VARIABLES:
          TEMP    F            300.0000         MISSING     300.0000
          PRES    PSI           14.6959         14.6959      14.6959
          VFRAC                  1.0000         MISSING       1.0000
          LFRAC                  0.0            MISSING       0.0
          SFRAC                  0.0            MISSING       0.0
        ENTHALPY:
          BTU/LBMOL          -1.2315+04         MISSING -2.6587+04
          BTU/LB              -430.4089         MISSING -1022.1591
          BTU/HR             -1.2315+06         MISSING -2.9249+06
        ENTROPY:
          BTU/LBMOL-R           -3.1492         MISSING    -0.2405
          BTU/LB-R              -0.1101         MISSING -9.2445-03
        DENSITY:
          LBMOL/CUFT          1.8027-03         MISSING    1.8027-03
          LB/CUFT             5.1577-02         MISSING    4.6888-02
        AVG MW                  28.6113         MISSING      26.0106


   Selected Process Unit Output
                                   *** RESULTS     ***
          OUTPUT TEMPERATURE        F                                         300.00
          OUTPUT PRESSURE           PSI                                       14.696
          HEAT DUTY                 BTU/HR                                  -0.16934E+07
          VAPOR FRACTION                                                      1.0000

          REACTION EQUILIBRIUM CONSTANTS:

            REACTION           EQUILIBRIUM
             NUMBER             CONSTANT
               1                1663.3
               2               0.99999+100
               3

c. Solution using the RGIBBS subroutine in ASPEN PLUS. This solution can be reproduced
   using the file, RGIBBS.BKP.




                                              – 46 –
Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course


                                                R1

                             FEED                           VAP



                                                     LIQ




               Note that when using the REQUIL subroutine, streams for both vapor and
               liquid effluents must be defined, even when one doesn’t exist.

               ASPEN PLUS Program – only those paragraphs that differ from the program
               above are included.
    TITLE 'CHEMICAL EQUILIBRIUM - MINIMIZATION OF G'

    BLOCK R1 RGIBBS
        PARAM TEMP=300. PRES=1. <atm>

Stream Variables
    FEED LIQ VAP
     ------------
     STREAM ID                   FEED        LIQ            VAP
     FROM :                      ----        R1             R1
     TO   :                      R1          ----           ----

     SUBSTREAM: MIXED
     PHASE:                  VAPOR           MISSING         VAPOR
     COMPONENTS: LBMOL/HR
       AMMON-01              20.0000           0.0            0.0
       OXYGEN                20.0000           0.0         1.5905-06
       NITRO-01              20.0000           0.0           10.0000
       NITRI-01              20.0000           0.0           50.0000
       WATER                 20.0000           0.0           50.0000
     TOTAL FLOW:
       LBMOL/HR             100.0000           0.0          110.0000
       LB/HR               2861.1264           0.0         2861.1264
       CUFT/HR             5.5473+04           0.0         6.1021+04
     STATE VARIABLES:
       TEMP    F            300.0000         MISSING        300.0000
       PRES    PSI           14.6959         MISSING         14.6959
       VFRAC                  1.0000         MISSING          1.0000
       LFRAC                  0.0            MISSING          0.0
       SFRAC                  0.0            MISSING          0.0
     ENTHALPY:
       BTU/LBMOL          -1.2315+04         MISSING -2.6588+04
       BTU/LB              -430.4089         MISSING -1022.2009
       BTU/HR             -1.2315+06         MISSING -2.9246+06
     ENTROPY:
       BTU/LBMOL-R           -3.1492         MISSING    -0.2403
       BTU/LB-R              -0.1101         MISSING -9.2405-03
     DENSITY:
       LBMOL/CUFT          1.8027-03         MISSING       1.8027-03
       LB/CUFT             5.1577-02         MISSING       4.6888-02
     AVG MW                  28.6113         MISSING         26.0102

           Note that these results are nearly identical to those for part ‘a’. Tight convergence
           tolerances are satisfied by the RGIBBS subroutine, while small material balance
           differences between the inlet and outlet streams are reported by the REQUIL
           subroutine.
                                            – 47 –
Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course


Selected Process Unit Output
    FLUID PHASE SPECIES IN PRODUCT LIST:
         AMMON-01 OXYGEN NITRO-01 NITRI-01 WATER

       ATOM MATRIX:
       ELEMENT        H      N      O
         AMMON-01     3.00   1.00   0.00
         OXYGEN       0.00   0.00   2.00
         NITRO-01     0.00   1.00   2.00
         NITRI-01     0.00   1.00   1.00
         WATER        2.00   0.00   1.00

                                *** RESULTS           ***
       TEMPERATURE            F                                            300.00
       PRESSURE               PSI                                          14.696
       HEAT DUTY              BTU/HR                                     -0.16932E+07
       VAPOR FRACTION                                                      1.0000
       NUMBER OF FLUID PHASES                                                       1
       FLUID PHASE MOLE FRACTIONS:

       PHASE                  VAPOR
       OF TYPE                VAPOR
       PHASE FRACTION         1.000000
       PLACED IN STREAM       VAP
         AMMON-01            0.0000000E+00
         OXYGEN              0.1445920E-07
         NITRI-01            0.4545455
         WATER               0.4545454




                                             – 48 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                                          Heat Transfer

HYSYS.Plant

        The materials supporting a course in heat transfer assume that two hours of computer
laboratory time is allocated to the exercises. The multimedia includes a section that provides a
self-paced overview on heat transfer equipment in general and the models available in
HYSYS.Plant in particular. The following sequence is suggested:

Session 1: In the first part of the exercise session, the student should review the entire section
           on HYSYS – Heat Exchangers in the multimedia. This consists of modules
           describing the simple heater/cooler and the more rigorous heat exchanger. The
           modules each illustrate the use of the models in example applications.




Session 2: The tutorial Toluene Manufacture should be reviewed, while at the same time, the
           student should develop his/her version of the simulation using HYSYS.Plant.




To reinforce their acquired capabilities, students should be assigned a homework exercise. Two
typical exercises are provided: (a) The rating of a 2-8 heat exchanger for process heat transfer;
(b) Completing the Toluene Manufacture heat-integrated process to determine the optimum pre-
heat temperature.




                                              – 49 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                                          Heat Transfer

ASPEN PLUS

        The materials supporting a course in heat transfer assume that two hours of computer
laboratory time is allocated to the exercises. The multimedia includes a section that provides a
self-paced overview on heat transfer equipment in general and the models available in ASPEN
PLUS in particular. The following sequence is suggested. Note that this sequence has not been
class-tested using ASPEN PLUS. However, a similar sequence using HYSYS.Plant, on the
previous page, has been class-tested successfully:

Session 1: In the first part of the exercise session, the student should review the first three
           sections on Heat Exchangers in the multimedia (1. Introduction with Videos, 2. Heat
           Requirement Modules, and 3. Shell-and-Tube Heat Exchangers.) These consist of
           modules describing the simple heater/cooler and the more rigorous heat exchanger.
           The modules each illustrate the use of the models in example applications. Note that
           videos are provided of industrial 1-2 shell-and-tube heat exchangers and fin-fan heat
           exchangers.




Session 2:   The student should review the tutorial involving Toluene Manufacture, while at the
             same time, develop his/her version of the simulation using ASPEN PLUS.




To reinforce their acquired capabilities, students should be assigned a homework exercise. Two
typical exercises are provided: (a) The rating of a 2-8 heat exchanger for process heat transfer;
(b) Completing the Toluene Manufacture heat-integrated process to determine the optimum pre-
heat temperature.
                                              – 50 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                         Exercise C.1 Heat Exchanger Rating Problem

         An existing 2-8 shell-and-tube heat exchanger is to be used to transfer heat to a toluene
feed stream from a styrene product stream. The toluene enters the exchanger on the tube side at a
flow rate of 125,000 lb/hr at 100oF and 90 psia. The styrene enters on the shell side at a flow rate
of 150,000 lb/hr at 300oF and 50 psia. The exchanger shell and tubes are carbon steel. The shell
has an inside diameter of 39 in. and contains 1,024 3/4-in., 14 BWG, 16-ft-long tubes on a 1-in.
square pitch. Thirty-eight segmental baffles are used with a baffle cut of 25%. Shell inlet and
outlet nozzles are 2.5-in., schedule 40 pipe, and tube-side inlet and outlet nozzles are 4-in.,
schedule 40 pipe. Fouling factors are estimated to be 0.002 (hr-ft2-oF)/Btu on each side.
Determine the exit temperatures of the two streams, the heat duty, and the pressure drops. In
ASPEN PLUS, use the HEATX subroutine, and in HYSYS.Plant, use Heat Exchanger. Note
that this problem is solved in Example 8.7 of Seider, Seader, and Lewin (1999).

                    HYSYS.Plant Solution                 ASPEN PLUS Solution

                         Exercise C.2 Heat Exchanger Design Problem

        Complete the class exercise in which a heat integrated process was developed for the
manufacture of toluene from n-heptane. You are required to determine the optimum pre-heat
temperature to minimize the annual cost, involving both the cost of the preheater and the energy
costs associated with preheating the feed stream. The following data is provided:
        U = 65 Btu/h ft2 °F (assumed constant)
        Cost of Super-heater Fuel = 0.02 $/Btu h-1 y-1
        Bare Modules Cost (for kettle reboiler), in $:
                        {
               CB = exp 11.967 − 0.8709 [ ln( A) ] + 0.09005 [ ln( A) ] ,
                                                                     2
                                                                         }
where A is the exchanger surface area in ft2. The annualized equipment cost, assuming 20%
depreciation, is CA = 1.05×4.8×CB/5

       It is suggested that you use the Spreadsheet to compute the annual costs based on the
above data and the Databook to carry out a sensitivity analysis to show the effect of preheat
temperature on annual cost. Your solution should include the following:
   a) A plot showing the annual cost as a function of the super-heater feed temperature. What is
       the maximum possible temperature attainable?
   b) A definition of the optimal value of the super-heater feed temperature, optimal pre-heater
       heat exchange area, and the corresponding annual cost.
   c) Comparison of the optimal annual cost incurred with that of the cases where (a) no
       preheater installed; (b) a preheater is installed to bring the n-heptane to its dew point.

                                           HYSYS.Plant Solution


                                                – 51 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                            Exercise C.1 Solution using HYSYS.Plant

                   These results can be reproduced using the file HEATEX.hsc

       The heat exchanger in HYSYS.Plant is used to make the calculations. In its rating mode,
it uses built-in correlations of the type described in Chapter 8 (Seider, Seader, and Lewin) for
estimating shell-side and tube-side heat-transfer coefficients and pressure drops. The following
results are obtained (both streams are liquid):
       Toluene exit temperature = 252.6 oF
       Styrene exit temperature = 179.3 oF
       Tube-side pressure drop = 0.02 psi (this is well-below expected)
       Toluene exit pressure = 89.98 psia
       Shell-side pressure drop = 0.716 psia (this is well-below expected)
       Styrene exit pressure = 54.28 psia
       Heat-transfer area (tube outside) = Two shells, with 1,608 ft2 per shell.
       Heat duty = 8.70×106 Btu/hr
       Estimated shell-side film coefficient =110.3 Btu/hr-ft2-R
       Estimated tube-side film coefficient = 393.7Btu/hr-ft2-R
       Estimated overall heat transfer coefficient = 58.1 Btu/hr-ft2-R
       Log-mean temperature difference based on countercurrent flow = 46.5 oF
       Correction factor for 2-8 exchanger, FT = 0.750




                                                  – 52 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                           Exercise C.1 Solution using ASPEN.PLUS

       The HEATX subroutine (block) of the ASPEN PLUS simulator is used to make the
calculations. It has built-in correlations of the type described in Chapter 8 (Seider, Seader, and
Lewin) for estimating shell-side and tube-side heat-transfer coefficients and pressure drops. The
following results are obtained (both streams are liquid):
       Toluene exit temperature = 255.0oF
       Styrene exit temperature = 178.1oF
       Tube-side tube pressure drop = 3.59 psi
       Tube-side nozzle pressure drop = 0.55 psi
       Toluene exit pressure = 85.86 psia
       Shell-side baffled pressure drop = 4.55 psia
       Shell-side nozzle pressure drop = 5.18 psia
       Styrene exit pressure = 40.28 psia
       Heat-transfer area (tube outside) = 3,217 ft2
       Heat duty = 8,625,200 Btu/hr
       Estimated (Uo) clean = 90.4 Btu/hr-ft2-R
       Estimated (Uo ) dirty = 64.0 Btu/hr-ft2-R
       Log-mean temperature difference based on countercurrent flow = 41.9oF
       Correction factor for 2-8 exchanger, FT = 0.712
       Velocity in the tubes = 3.02 ft/s
       Maximum Reynolds number in the tubes = 45,700
       Crossflow velocity in the shell = 2.59 ft/s
       Maximum crossflow Reynolds number in the shell = 50,300
       Flow regime on tube and shell sides = turbulent


ASPEN PLUS Program

   TITLE 'HEAT EXCHANGER DESIGN - EXAMPLE 13.7 (OLD 8.7)'
   IN-UNITS ENG
   DEF-STREAMS CONVEN ALL
   DESCRIPTION "
        General Simulation with English Units :
        F, psi, lb/hr, lbmol/hr, Btu/hr, cuft/hr.
        Property Method: None
        Flow basis for input: Mole
                                               – 53 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

       Stream report composition: Mole flow
   DATABANKS PURE11 / AQUEOUS       / SOLIDS    / INORGANIC    /   &
           NOASPENPCD
   PROP-SOURCES PURE11     / AQUEOUS    / SOLIDS    / INORGANIC
   COMPONENTS
       TOLUENE C7H8 /
       STYRENE C8H8
   FLOWSHEET
       BLOCK H1 IN=HOTIN COLDIN OUT=HOTOUT COLDOUT
   PROPERTIES RK-SOAVE
       PROPERTIES BWR-LS / BWRS / CHAO-SEA / IDEAL / LK-PLOCK /
           PENG-ROB
   STREAM COLDIN
       SUBSTREAM MIXED TEMP=100. PRES=90. MASS-FLOW=125000.            &
           FREE-WATER=NO NPHASE=2 PHASE=V
       MOLE-FRAC TOLUENE 1. / STYRENE 0.
   STREAM HOTIN
       SUBSTREAM MIXED TEMP=300. PRES=50. MASS-FLOW=150000.
       MOLE-FRAC TOLUENE 0. / STYRENE 1.
   BLOCK H1 HEATX
       PARAM CALC-TYPE=SIMULATION AREA=3217. TYPE=COUNTERCURRE              &
            NPOINTS=5 P-UPDATE=YES U-OPTION=FILM-COEF &
            F-OPTION=GEOMETRY CALC-METHOD=DETAILED FC-USE-AVTD=YES
       FEEDS HOT=HOTIN COLD=COLDIN
       PRODUCTS HOT=HOTOUT COLD=COLDOUT
       HEAT-TR-COEF SCALE=1.
       FLASH-SPECS HOTOUT NPHASE=1 PHASE=L FREE-WATER=NO
       FLASH-SPECS COLDOUT NPHASE=1 PHASE=L FREE-WATER=NO
       EQUIP-SPECS TUBE-NPASS=8 TEMA-TYPE=F SHELL-DIAM=39. <in>                &
           SHELL-BND-SP=0.25 <in>
       TUBES TOTAL-NUMBER=1024 PATTERN=SQUARE LENGTH=16.           &
            INSIDE-DIAM=0.584 <in> OUTSIDE-DIAM=0.75 <in> PITCH=1. <in>                &
            TCOND=25.
       NOZZLES SNOZ-INDIAM=2.469 <in> SNOZ-OUTDIAM=2.469 <in>              &
           TNOZ-INDIAM=4.026 <in> TNOZ-OUTDIAM=4.026 <in>
       SEGB-SHELL NBAFFLE=38 NSEAL-STRIP=1 BAFFLE-CUT=0.25 &
           SHELL-BFL-SP=0.1 <in> TUBE-BFL-SP=0.1 <in> IN-BFL-SP=0.6                &
           OUT-BFL-SP=0.6
       HOT-HCURVE 1 NPOINT=20
       COLD-HCURVE 1 NPOINT=20
       HOT-SIDE H-OPTION=GEOMETRY H-SCALE=1. FOUL-FACTOR=0.002              &
           SHELL-TUBE=SHELL DP-OPTION=GEOMETRY
       COLD-SIDE H-OPTION=GEOMETRY H-SCALE=1. FOUL-FACTOR=0.002                &
           DP-OPTION=GEOMETRY
       REPORT PROFILE
   EO-CONV-OPTI
   STREAM-REPOR MOLEFLOW
------------------------------------------------------------------------
Stream Variables
                                               – 54 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course


    COLDIN COLDOUT HOTIN HOTOUT
    ---------------------------
    STREAM ID               COLDIN               COLDOUT    HOTIN         HOTOUT
    FROM :                  ----                 H1         ----          H1
    TO   :                  H1                   ----       H1            ----
    SUBSTREAM: MIXED
    PHASE:                       LIQUID          LIQUID      LIQUID       LIQUID
    COMPONENTS: LBMOL/HR
      TOLUENE                  1356.6236    1356.6236         0.0          0.0
      STYRENE                     0.0          0.0         1440.2094    1440.2094
    TOTAL FLOW:
      LBMOL/HR                 1356.6236    1356.6236      1440.2094    1440.2094
      LB/HR                    1.2500+05    1.2500+05      1.5000+05    1.5000+05
      CUFT/HR                  2353.1302    2618.0856      3140.9333    2899.5818
    STATE VARIABLES:
      TEMP    F                 100.0000        254.9779    300.0000     178.1253
      PRES    PSI                90.0000         85.8741     50.0000      40.2773
      VFRAC                       0.0             0.0         0.0          0.0
      LFRAC                       1.0000          1.0000      1.0000       1.0000
      SFRAC                       0.0             0.0         0.0          0.0
    ENTHALPY:
      BTU/LBMOL                6023.3178    1.2381+04      5.4993+04    4.9004+04
      BTU/LB                     65.3710     134.3724       528.0063     470.5051
      BTU/HR                   8.1714+06    1.6797+07      7.9201+07    7.0576+07
    ENTROPY:
      BTU/LBMOL-R              -80.0905         -70.1012   -62.6490      -71.2187
      BTU/LB-R                  -0.8692          -0.7608    -0.6015       -0.6838
    DENSITY:
      LBMOL/CUFT                  0.5765          0.5182      0.4585       0.4967
      LB/CUFT                    53.1207         47.7448     47.7565      51.7316
    AVG MW                       92.1405         92.1405    104.1515     104.1515

Selected Process Unit Output
BLOCK: H1        MODEL: HEATX
 -----------------------------
   FLOW DIRECTION AND SPECIFICATION:
     COUNTERCURRENT   HEAT EXCHANGER
     SPECIFIED EXCHANGER AREA
     SPECIFIED VALUE                 SQFT                              3217.0000

   EQUIPMENT SPECIFICATIONS:
     NUMBER OF SHELL PASSES                                               2
     NUMBER OF TUBE PASSES                                                8
     TEMA SHELL TYPE                                                    F
     ORIENTATION                                                        HORIZONTAL
     BAFFLE TYPE                                                        SEGMENTAL
     SHELL INSIDE DIAMETER                 FT                            3.2500
     SHELL TO BUNDLE CLEARANCE             FT                            0.0208
   SPECIFICATIONS FOR TUBES:
     TOTAL NUMBER OF TUBES                                             1024
     TUBE TYPE                                                           BARE
     TUBE PATTERN                                                        SQUARE
     TUBE MATERIAL                                                       CARBON-STEEL
     TUBE LENGTH                           FT                            16.0000
     TUBE INSIDE DIAMETER                  FT                             0.0487
     TUBE OUTSIDE DIAMETER                 FT                             0.0625
     TUBE PITCH                            FT                             0.0833
     TUBE THERMAL CONDUCTIVITY             BTU-FT/HR-SQFT-R              25.0000

   SPECIFICATIONS FOR SEGMENTAL BAFFLE SHELL:
     NUMBER OF BAFFLES                                                   38
     NUMBER OF SEALING STRIP PAIRS                                        1
     TUBES IN WINDOW                                                     YES
     BAFFLE CUT                                                           0.2500
     SHELL TO BAFFLE CLEARANCE      FT                                    0.0083
     TUBE TO BAFFLE CLEARANCE       FT                                    0.0083
     CENTRAL BAFFLE SPACING         FT                                    0.8222
     INLET BAFFLE SPACING           FT                                    0.6000
                                                  – 55 –
Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

  OUTLET BAFFLE SPACING               FT                           0.6000
SPECIFICATIONS FOR NOZZLES:
  SHELL INLET NOZZLE DIAMETER         FT                           0.2058
  SHELL OUTLET NOZZLE DIAMETER        FT                           0.2058
  TUBE INLET NOZZLE DIAMETER          FT                           0.3355
  TUBE OUTLET NOZZLE DIAMETER         FT                           0.3355

                        ***   OVERALL RESULTS    ***
STREAMS:
               --------------------------------------
               |                                    |
HOTIN    ----->|            HOT (SHELL)             |----->           HOTOUT
T= 3.0000D+02 |                                     |                 T= 1.7813D+02
P= 5.0000D+01 |                                     |                 P= 4.0277D+01
V= 0.0000D+00 |                                     |                 V= 0.0000D+00
               |                                    |
COLDOUT  <-----|            COLD (TUBE)             |<-----           COLDIN
T= 2.5498D+02 |                                     |                 T= 1.0000D+02
P= 8.5874D+01 |                                     |                 P= 9.0000D+01
V= 0.0000D+00 |                                     |                 V= 0.0000D+00
               --------------------------------------

DUTY AND AREA:
  CALCULATED HEAT DUTY                BTU/HR                8625176.3970
  CALCULATED (REQUIRED) AREA          SQFT                     3216.9807
  ACTUAL EXCHANGER AREA               SQFT                     3217.0000
  PER CENT OVER-DESIGN                                            0.0006

HEAT TRANSFER COEFFICIENT:
  AVERAGE COEFFICIENT (DIRTY)         BTU/HR-SQFT-R               63.9835
  AVERAGE COEFFICIENT (CLEAN)         BTU/HR-SQFT-R               90.4114
LOG-MEAN TEMPERATURE DIFFERENCE:
  THERMAL EFFECTIVENESS (XI)                                       0.7777
  NUMBER OF TRANSFER UNITS (NTU)                                   3.6905
  LMTD CORRECTION FACTOR                                           0.7116
  LMTD (CORRECTED)               F                                41.9036

STREAM VELOCITIES:
  SHELLSIDE MAX. CROSSFLOW VEL. FT/SEC                            2.5906
  SHELLSIDE MAX. CROSSFLOW REYNOLDS NO.                       50327.8397
  SHELLSIDE MAX. WINDOW VEL.     FT/SEC                           2.0860
  SHELLSIDE MAX. WINDOW REYNOLDS NO.                          40525.1971
  TUBESIDE MAX. VELOCITY         FT/SEC                           3.0208
  TUBESIDE MAX. REYNOLDS NO.                                  45680.4836

PRESSURE DROP:
  SHELLSIDE, BAFFLED FLOW AREA        PSI                          4.5462
  SHELLSIDE, NOZZLE                   PSI                          5.1766
  SHELLSIDE, TOTAL                    PSI                          9.7228
  TUBESIDE, TUBES                     PSI                          3.5838
  TUBESIDE, NOZZLE                    PSI                          0.5421
  TUBESIDE, TOTAL                     PSI                          4.1259

PRESSURE DROP PARAMETER:
  SHELL SIDE:                                                149301.6600
  TUBE SIDE:                                                  92382.6749

                        ***   ZONE PROFILES    ***
ZONE 1:
-----------

SHELLSIDE:
                         CROSSFLOW/WINDOW        CROSSFLOW/WINDOW
      TEMPERATURE            VELOCITY            REYNOLDS NUMBER         PRANDTL NUMBER
POINT      F                 FT/SEC
  1     288.526           2.591/    2.086        50327.8/   40525.2           4.342
  2     265.138           2.549/    2.052        46299.3/   37281.3           4.485
  3     241.133           2.508/    2.020        42175.1/   33960.4           4.673
  4     216.468           2.469/    1.988        37975.8/   30579.0           4.921
  5     191.094           2.430/    1.957        33728.7/   27159.1           5.246


                                            – 56 –
  Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

 TUBESIDE:
         TEMPERATURE         VELOCITY              REYNOLDS NUMBER         PRANDTL NUMBER
 POINT        F              FT/SEC
   1       240.793              3.021                   45680.5                 4.234
   2       211.649              2.956                   39388.8                 4.572
   3       181.392              2.893                   33807.1                 4.948
   4       149.899              2.833                   28784.9                 5.382
   5       117.018              2.774                   24146.0                 5.921
 HEAT TRANSFER:

          WALL TEMP.         HS              HT              U                 AREA
 POINT        F              <----     BTU/HR-SQFT-R      ---->                SQFT
   1       256.885        164.203         322.868          66.895             759.218
   2       230.204        161.888         304.803          65.481             692.152
   3       202.722        159.126         286.554          63.909             634.956
   4       174.391        155.866         267.773          62.139             586.064
   5       145.187        152.050         247.796          60.094             544.591


HEATX COLD-HCURVE: H1        HCURVE 1
-------------------------------------
  INDEPENDENT VARIABLE: DUTY
  PRESSURE PROFILE:      CONSTANT
  PROPERTY OPTION SET:   RK-SOAVE STANDARD RKS EQUATION OF STATE
-----------------------------------------------------
! DUTY       ! PRES       ! TEMP       ! VFRAC      !
!            !            !            !            !
!            !            !            !            !
!            !            !            !            !
! BTU/HR     ! PSI        ! F          !            !
!            !            !            !            !
!============!============!============!============!
!     0.0    !    85.8741 !   100.0291 !     0.0    !
! 4.1072+05 !     85.8741 !   108.1814 !     0.0    !
! 8.2145+05 !     85.8741 !   116.2416 !     0.0    !
! 1.2322+06 !     85.8741 !   124.2125 !     0.0    !
! 1.6429+06 !     85.8741 !   132.0969 !     0.0    !
!------------+------------+------------+------------!
! 2.0536+06 !     85.8741 !   139.8974 !     0.0    !
! 2.4643+06 !     85.8741 !   147.6163 !     0.0    !
! 2.8751+06 !     85.8741 !   155.2561 !     0.0    !
! 3.2858+06 !     85.8741 !   162.8189 !     0.0    !
! 3.6965+06 !     85.8741 !   170.3070 !     0.0    !
!------------+------------+------------+------------!
! 4.1072+06 !     85.8741 !   177.7224 !     0.0    !
! 4.5179+06 !     85.8741 !   185.0669 !     0.0    !
! 4.9287+06 !     85.8741 !   192.3424 !     0.0    !
! 5.3394+06 !     85.8741 !   199.5507 !     0.0    !
! 5.7501+06 !     85.8741 !   206.6935 !     0.0    !
!------------+------------+------------+------------!
! 6.1608+06 !     85.8741 !   213.7722 !     0.0    !
! 6.5716+06 !     85.8741 !   220.7884 !     0.0    !
! 6.9823+06 !     85.8741 !   227.7435 !     0.0    !
! 7.3930+06 !     85.8741 !   234.6388 !     0.0    !
! 7.8037+06 !     85.8741 !   241.4755 !     0.0    !
!------------+------------+------------+------------!
! 8.2145+06 !     85.8741 !   248.2548 !     0.0    !
! 8.6252+06 !     85.8741 !   254.9779 !     0.0    !
-----------------------------------------------------

HEATX HOT-HCURVE:   H1       HCURVE 1
-------------------------------------
  INDEPENDENT VARIABLE: DUTY
  PRESSURE PROFILE:      CONSTANT
  PROPERTY OPTION SET:   RK-SOAVE STANDARD RKS EQUATION OF STATE
-----------------------------------------------------
! DUTY       ! PRES       ! TEMP       ! VFRAC      !
!            !            !            !            !
!            !            !            !            !

                                             – 57 –
  Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

!            !            !            !            !
! BTU/HR     ! PSI        ! F          !            !
!            !            !            !            !
!============!============!============!============!
!     0.0    !    40.2773 !   300.0369 !     0.0    !
! -4.1072+05 !    40.2773 !   294.5902 !     0.0    !
! -8.2145+05 !    40.2773 !   289.1111 !     0.0    !
! -1.2322+06 !    40.2773 !   283.5989 !     0.0    !
! -1.6429+06 !    40.2773 !   278.0534 !     0.0    !
!------------+------------+------------+------------!
! -2.0536+06 !    40.2773 !   272.4740 !     0.0    !
! -2.4643+06 !    40.2773 !   266.8601 !     0.0    !
! -2.8751+06 !    40.2773 !   261.2113 !     0.0    !
! -3.2858+06 !    40.2773 !   255.5271 !     0.0    !
! -3.6965+06 !    40.2773 !   249.8068 !     0.0    !
!------------+------------+------------+------------!
! -4.1072+06 !    40.2773 !   244.0498 !     0.0    !
! -4.5179+06 !    40.2773 !   238.2557 !     0.0    !
! -4.9287+06 !    40.2773 !   232.4237 !     0.0    !
! -5.3394+06 !    40.2773 !   226.5533 !     0.0    !
! -5.7501+06 !    40.2773 !   220.6438 !     0.0    !
!------------+------------+------------+------------!
! -6.1608+06 !    40.2773 !   214.6946 !     0.0    !
! -6.5716+06 !    40.2773 !   208.7049 !     0.0    !
! -6.9823+06 !    40.2773 !   202.6741 !     0.0    !
! -7.3930+06 !    40.2773 !   196.6014 !     0.0    !
! -7.8037+06 !    40.2773 !   190.4863 !     0.0    !
!------------+------------+------------+------------!
! -8.2145+06 !    40.2773 !   184.3278 !     0.0    !
! -8.6252+06 !    40.2773 !   178.1253 !     0.0    !
-----------------------------------------------------




                                             – 58 –
Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                         Exercise C.2 Solution using HYSYS.Plant


 These results can be reproduced using the file: TOLUENE_MANUFACTURE_EX.HSC


a) The annual costs computed using HYSYS is plotted below. The maximum
    possible preheat temperature is 617 oF (here the temperature profiles in the heat
    exchanger are almost pinched).




b) From the above results, it is noted that the optimal pre-heat temperature is 600 oF,
    at which the annual cost is $369,500. For this value of pre-heat temperature, the
    required heat transfer area is 7,110 ft2
c) The total annual cost with no pre-heating is $1,173,000. To bring the n-heptane to
    its dew point, the pre-heat temperature needs to be 209.3 oF (computed by setting
    the vapor fraction to unity), for which the annual cost is $765,300.




                                               – 59 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                                           Separations

HYSYS.Plant

       The materials supporting a course in separations assume that the students have already
covered most of the theory on multicomponent separations (flash and distillation). It is
recommended that 1-2 hours of computer laboratory time be allocated to allow students to review
the multimedia support available. The following sequence of modules is recommended:

Session 1: Cover all of the material under HYSYS – Separations in the multimedia: Click on
           Overview, and the cover all of the materials supporting Flash and Distillation. The
           latter provides a framework for systematic multicomponent distillation column
           design, in which the Component Splitter assists in the selection of operating
           pressure, the Short-cut Column, using FUG methods, is employed to estimate the
           number of stages, the location of the feed tray, and the required reflux ratio, and
           finally the Column is used for the rigorous solution of MESH equations.




Session 2: Many students require assistance in the correct selection of property estimation
           methods. It may be helpful to review the module on Physical Property Estimation –
           Package Selection. Advanced students are encouraged to also review the tutorial on
           multi-draw tower optimization.




To reinforce their acquired capabilities, students should be assigned one or more homework
exercises. Two example exercises are provided: (a) The design of a series of two columns for the
separation of a mixture of alcohols; (b) A single multicomponent column.

                                              – 60 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                                           Separations

ASPEN PLUS

       The materials supporting a course in separations assume that the students have already
covered most of the theory on multicomponent separations (flash and distillation). It is
recommended that 1-2 hours of computer laboratory time be allocated to allow students to review
the multimedia support available. The following sequence of modules is recommended:

Session 1:   Under ASPEN – Tutorials – Separations, the main menu refers to item 2.
             Distillation. Students should see the videos of an industrial distillation complex and
             a laboratory tower. Then, they should review the module on Split-fraction Model
             (SEP2), which shows how to set the tower pressure, given specifications of the split
             fractions. Then, they should refer to the module on FUG Shortcut Design (DSTWU)
             to review methods for estimating the number of trays, the feed tray, and the reflux
             ratio. Finally, they should review the module on MESH Equations (RADFRAC)




Session 2:   Many students require assistance in the correct selection of property estimation
             methods. It may be helpful to review the module on Physical Property Estimation –
             Package Selection.

To reinforce their acquired capabilities, students should be assigned one or more homework
exercises. Two typical exercises are provided: (a) The design of a series of two columns for the
separation of a mixture of alcohols; (b) A single multicomponent column.


ICARUS Process Evaluator (IPE)

         IPE, an Aspen Tech product, takes results from any of the major process simulators,
involving many kinds of equipment items, and estimates equipment sizes, purchase costs and
installation costs leading to the total capital investment, operating costs, and profitability
measures. WDS has developed a set of course notes, which are provided with these materials.
Also, he is developing multimedia materials to provide instruction on the use of IPE. Eventually,
these can be used in the separations course to estimate the investment costs for a distillation
complex, as well as other separators. In these materials, we are providing Exercise 9.1 (SSL),
which involves the sizing and costing of a distillation complex. Exercise 9.1 has been modified
to include the usage of IPE.


                                              – 61 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                 Exercise D.1 Multicomponent Distillation Design Problem 1

       In the manufacture of higher alcohols from carbon monoxide and hydrogen, a mixture of
alcohols is obtained, which must be separated into desired products. A feed mixture of:

                                               mol%
                               ethanol          25
                               n-propanol       50
                               iso-butanol      10
                               n-butanol        15
has been isolated from methanol and heavier alcohols in prior distillation steps. It is a saturated
liquid at the pressure of the first distillation column, to be determined in ‘a’ below.

       The three desired products are streams containing:

1. At least 98% of the ethanol at a purity of 98 mol%.

2. N-propanol with essentially all of the remaining ethanol and no more than 2% of the
   isobutanol in the feed mixture.

3. At least 98% of the iso-butanol, all of the n-butanol, and no more than 1% of the n-propanol,
   in the feed mixture.

Two distillation towers are used. The first receives the feed mixture. Its distillate is fed to the
second tower, which produces ethanol-rich and n-propanol-rich products.

Use a process simulator to:

a. Determine the tower pressures that permit cooling water to be used in the condensers; that is,
   let the cooling water be heated from 90-120°F and the bubble-point of the condensed
   overhead vapor be 130°F or higher. This assures that the minimum approach temperature
   difference is 10°F. Use total condensers. To avoid vacuum operation, pressures in the towers
   must exceed 20 psia. Assume no pressure drop in the towers. In ASPEN PLUS, use the
   SEP2 subroutine. In HYSYS.Plant, use Splitter.

b. Determine the minimum number of trays and the minimum reflux ratio. Then, let the actual
   reflux ratio be 1.3 × Rmin and use the Gilliland correlation to determine the theoretical number
   of trays and the location of the feed tray. In ASPEN PLUS, use the DSTWU subroutine. In
   HYSYS.Plant, use Short-cut Column.

c. Using the design determined in a and b, simulate the towers; that is, solve the MESH
   equations. In ASPEN PLUS, use the RADFRAC subroutine. In HYSYS.Plant, use Column.

                   HYSYS.Plant Solution                ASPEN PLUS Solution



                                              – 62 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                 Exercise D.2 Multicomponent Distillation Design Problem 2


       The composition of a stream of 100 kgmol/hr at of a multicomponent mixture is:

                                                 mol%
                         benzene                  12.5
                         toluene                  22.5
                         o-xylene                 37.5
                         n-propylbenzene          27.5

It is required to design a distillation column to separate the mixture such that the distillate
contains at least 99% of the toluene and the bottoms at least 99.4% of the o-xylene, given that the
stream is supplied at its bubble point, and both of the product streams are to be drawn as liquids.

Use a process simulator to:

 (a)    Determine the tower pressure that permit cooling water to be used in the condenser;
        that is, let the cooling water be heated from 25-40°C and the bubble-point of the
        condensed overhead vapor 50°C, with a lower bound on the operating pressure
        being 20 psia. You may neglect the pressure drop in the column throughout this
        exercise. In ASPEN PLUS, use the SEP2 subroutine. In HYSYS.Plant, use
        Splitter.
 (b)    Determine the minimum number of trays and the minimum reflux ratio. Then, let
        the actual reflux ratio be 1.3 × Rmin and use the Gilliland correlation to determine
        the theoretical number of trays and the location of the feed tray. In ASPEN PLUS,
        use the DSTWU subroutine. In HYSYS.Plant, use Short-cut Column.
 (c)    Using the design determined in a and b, simulate the towers; that is, solve the
        MESH equations.      In ASPEN PLUS, use the RADFRAC subroutine. In
        HYSYS.Plant, use Column.
 (d)    Following fouling of the heat transfer surface in the reboiler, it is estimated that the
        available heat transfer duty has dropped by 40%. Is it possible to make a design
        change in the column to allow the two specifications met previously to be
        maintained? Alternatively, without changing the number of trays or the location of
        the feed tray determined previously, what is the reflux ratio that will allow at
        recovery of at least 90% of the toluene and 90% of the o-xylene for the fouled
        reboiler?


                                    HYSYS.Plant Solution




                                              – 63 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

Exercise D.3 Distillation Sizing and Costing Problem (Exercise 9.1 (SSL) – Revised for IPE)


        The feed to a sieve-tray distillation column operating at 1 atm is 700 lbmol/hr of 45 mol%
benzene and 55 mol% toluene at 1 atm and its bubble-point temperature of 201°F. The distillate
contains 92 mol% benzene and boils at 179°F. The bottoms product contains 95 mol% toluene
and boils at 227°F. The column has 23 trays spaced 18 in. apart, and its reflux ratio is 1.25.
Column pressure drop is neglected. Tray efficiency is 80%. Estimate the total bare-module cost
of the column, condenser, reflux accumulator, condenser pump, reboiler, and reboiler pump.
Also, estimate the total permanent investment. Results should be computed using: (1) the cost
charts in Chapter 9, and (2) IPE (ICARUS Process Evaluator). Compare the results.

Data
Molal heat of vaporization of distillate = 13,700 Btu/lbmol
Molal heat capacity of distillate = 40 Btu/lbmol °F
Overall U of condenser = 100 Btu/hr ft2 °F
Cooling water from 90°F to 120°F
Heat flux for reboiler = 12,000 Btu/hr ft2
Saturated steam at 60 psia
Reflux accumulator residence time = 5 minutes at half full; L/D = 4
Pump heads = 50 psia; suction pressure = 1 atm, efficiency = 1

Calculate the flooding velocity of the vapor using the procedure in Example 10.2. Use 85 percent
of the flooding velocity to determine the column diameter.

Notes

        The file, BENTOLDIST.BKP, is included on the CD-ROM that accompanies these notes.
It contains the simulation results using the RADFRAC subroutine in ASPEN PLUS. This file
should be used to prepare the report file for IPE. Note that the simulation was carried out using
20 stages (18 trays plus the condenser and reboiler). When using IPE, set the tray efficiency to
0.8 and IPE will adjust the number of trays to 23.

        Since IPE does not size and cost a reboiler pump, a centrifugal pump should be added.
Also, since Chapter 9 does not include the cost charts for a pump, copies from Ulrich (1984) are
attached.

        IPE estimates the physical properties and heat-transfer coefficients. Do not adjust these.

        In IPE, reset the temperatures of cooling water (90 and 120°F) and add a utility for 60
psia steam. Use the steam tables to obtain the physical properties.

        Use a kettle reboiler with a floating head.


                                                – 64 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

       IPE sizes the tower using a 24 in tray spacing as the default. After sizing (mapping) is
complete, adjust the tray spacing to 18 in. Note that the height of the tower must be adjusted
accordingly.

       Note that IPE estimates the costs of Direct Material and Manpower for each equipment
item. These are also referred to as the costs of direct materials and labor, CDML = CP + CM + CL.

To Be Submitted

        Include your hand calculations using the cost charts and the methods in Chapter 9. (Note
that these methods are identical to those in Example 10.2).

       Do not submit the entire IPE Capital Estimate Report. Instead, prepare a table showing a
comparison of the equipment sizes and purchased costs. When using the methods in Chapter 9,
show the bare module cost. For IPE, show the direct cost of materials and labor. It is sufficient
to take the numbers from IPE. For both methods, show the calculations leading to the total
permanent investment. Discuss the results.


                                    ASPEN PLUS Solution




                                              – 65 –
     Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                             Exercise D.1 Solution using HYSYS.Plant

                            Solution reproduced in: DISTIL_EX_1.hsc

       Based upon the specifications, the desired product streams are determined by material
balance:

                             FEED       D1          B1        D2         B2
                 Ethanol       25.0      25.0          -      24.5        0.5
               1-Propanol      50.0      49.5        0.5       0.5       49.0
                i-Butanol      10.0        0.2       9.8         -        0.2
               1- Butanol      15.0          -      15.0         -          -
                   Total      100.0      74.7       25.3      25.0       49.7

a.                  In HYSYS.Plant, the column pressures are determined using the Component
                    Splitter, adjusting the distillate pressure to achieve distillate bubble points at
                    130°F, with lower bounds of 20 psia to avoid vacuum operation. Note that
                    because the most volatile species, ethanol, is present in the distillate of both
                    towers, the pressure is adjusted to its lower bound in both towers.




Component Splitter: X-100
PARAMETERS
Stream Specifications
Overhead Pressure: 20.00 psia       Overhead Vapour Fraction: 0.0000
Bottoms Pressure: 20.00 psia        Bottoms Vapour Fraction: 0.0000
SPLITS
Component Fraction To Overhead
Component                           Overhead Fraction
Ethanol                                                              1
1-Propanol                                                        0.99

PROPERTIES
                                                 – 66 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

F1                                         Overall            Liquid Phase         Vapour Phase
Vapour/Phase Fraction                                    0                    1                     0
Temperature: (F)                                     215.7                215.7                 215.7
Pressure: (psia)                                        20                   20                    20
Molar Flow (lbmole/hr)                                 100                  100                     0
Mass Flow (lb/hr)                                     6010                 6010                     0
Liquid Volume Flow (barrel/day)                      511.6                511.6                     0
Molar Enthalpy (Btu/lbmole)                     -1.24E+05            -1.24E+05             -1.05E+05
Mass Enthalpy (Btu/lb)                               -2065                -2065                 -1882
Molar Entropy (Btu/lbmole-F)                         13.49                13.49                 36.13
Mass Entropy (Btu/lb-F)                             0.2245               0.2245                0.6496
Heat Flow (Btu/hr)                              -1.24E+07            -1.24E+07                      0

D1                                         Overall            Liquid Phase         Vapour Phase
Vapour/Phase Fraction                                     0                    1                    0
Temperature: (F)                                     207.6                207.6                 207.6
Pressure: (psia)                                        20                    20                   20
Molar Flow (lbmole/hr)                                 74.7                 74.7                    0
Mass Flow (lb/hr)                                     4141                 4141                     0
Liquid Volume Flow (barrel/day)                      353.7                353.7                     0
Molar Enthalpy (Btu/lbmole)                     -1.21E+05            -1.21E+05             -1.03E+05
Mass Enthalpy (Btu/lb)                               -2188                -2188                 -1947
Molar Entropy (Btu/lbmole-F)                         9.962                9.962                 34.28
Mass Entropy (Btu/lb-F)                             0.1797               0.1797                0.6464
Heat Flow (Btu/hr)                              -9.06E+06            -9.06E+06                      0

B1                                         Overall            Liquid Phase         Vapour Phase
Vapour/Phase Fraction                                     0                    1                    0
Temperature: (F)                                     251.5                251.5                 251.5
Pressure: (psia)                                        20                    20                   20
Molar Flow (lbmole/hr)                                 25.3                 25.3                    0
Mass Flow (lb/hr)                                     1868                 1868                     0
Liquid Volume Flow (barrel/day)                      157.9                157.9                     0
Molar Enthalpy (Btu/lbmole)                     -1.31E+05            -1.31E+05             -1.15E+05
Mass Enthalpy (Btu/lb)                               -1778                -1778                 -1558
Molar Entropy (Btu/lbmole-F)                         21.03                21.03                 43.53
Mass Entropy (Btu/lb-F)                             0.2848               0.2848                0.5912
Heat Flow (Btu/hr)                              -3.32E+06            -3.32E+06                      0




                                              – 67 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course


Component Splitter: X-101

PARAMETERS
Stream Specifications
Overhead Pressure: 20.00 psia  Overhead Vapour Fraction: 1.0000
Bottoms Pressure: 20.00 psia   Bottoms Vapour Fraction: 0.0000
SPLITS
Component Fraction To Overhead
Component                      Overhead Fraction
Ethanol                                                       0.98
1-Propanol                                                 0.0101

PROPERTIES
                                  Overall                              Liquid Phase Vapour Phase
D1                                                                 0                 1          0
Vapour/Phase Fraction                                         207.6             207.6       207.6
Temperature: (F)                                                 20                20          20
Pressure: (psia)                                                74.7              74.7          0
Molar Flow (lbmole/hr)                                         4141              4141           0
Mass Flow (lb/hr)                                             353.7             353.7           0
Liquid Volume Flow (barrel/day)                          -1.21E+05         -1.21E+05   -1.03E+05
Molar Enthalpy (Btu/lbmole)                                   -2188             -2188       -1947
Mass Enthalpy (Btu/lb)                                        9.962             9.962       34.28
Molar Entropy (Btu/lbmole-F)                                 0.1797            0.1797      0.6464
Mass Entropy (Btu/lb-F)                                  -9.06E+06         -9.06E+06            0
Heat Flow (Btu/hr)
                                  Overall                           Vapour Phase Liquid Phase
D2                                                                1             1             0
Vapour/Phase Fraction                                         188.1         188.1         188.1
Temperature: (F)                                                 20            20            20
Pressure: (psia)                                                 25            25             0
Molar Flow (lbmole/hr)                                         1159          1159             0
Mass Flow (lb/hr)                                             99.65         99.65             0
Liquid Volume Flow (barrel/day)                          -9.95E+04     -9.95E+04     -1.16E+05
Molar Enthalpy (Btu/lbmole)                                   -2147         -2147         -2487
Mass Enthalpy (Btu/lb)                                        31.08         31.08         6.095
Molar Entropy (Btu/lbmole-F)                                 0.6705        0.6705        0.1307
Mass Entropy (Btu/lb-F)                                  -2.49E+06     -2.49E+06              0
Heat Flow (Btu/hr)
                                  Overall                            Liquid Phase Vapour Phase
B2                                                                 0              1           0
Vapour/Phase Fraction                                         221.6           221.6       221.6
Temperature: (F)                                                 20              20          20
Pressure: (psia)                                                49.7           49.7           0
Molar Flow (lbmole/hr)                                         2983            2983           0
Mass Flow (lb/hr)                                               254             254           0
Liquid Volume Flow (barrel/day)                          -1.24E+05       -1.24E+05   -1.07E+05
Molar Enthalpy (Btu/lbmole)                                   -2062           -2062       -1789
                                              – 68 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

Mass Enthalpy (Btu/lb)                                            10.7          10.7       35.11
Molar Entropy (Btu/lbmole-F)                                   0.1783        0.1783       0.5865
Mass Entropy (Btu/lb-F)                                    -6.15E+06     -6.15E+06             0
Heat Flow (Btu/hr)



   b. Using the tower pressures determined in ‘a’, the numbers of trays and the reflux ratios are
      determined using short-cut column in HYSYS.Plant, for splits specified to give the
      desired products. For the first column, the minimum number of trays is 22. For 1.3Rmin,
      the design calls for 44 trays with reflux ratio of 2.298. For the second column, Nmin = 12,
      with a design for 1.3Rmin giving 23 trays and a reflux ratio of 3.604.




Shortcut Column: T-100B
Parameters
                          Component         Mole Fraction
Light Key                 1-Propanol                            1.98E-02
Heavy Key                 i-Butanol                             2.70E-03
Pressures (psia)          Reflux Ratios
Condenser Pressure                       20 External Reflux Ratio             2.298
Reboiler Pressure                        20 Minimum Reflux Ratio              1.768
User Variables
Results Summary
Trays / Temperatures      Flows
Minimum # of Trays                    21.52 Rectify Vapour (lbmole/hr)        246.4
Actual # of Trays                     43.63 Rectify Liquid (lbmole/hr)        171.7
Optimal Feed Stage                     24.7 Stripping Vapour (lbmole/hr)      246.4
Condenser Temperature (F)             207.6 Stripping Liquid (lbmole/hr)      271.7
Reboiler Temperature (F)              251.5 Condenser Duty (Btu/hr)      -4.11E+06
                                            Reboiler Duty (Btu/hr)        4.14E+06




                                                – 69 –
    Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course


Shortcut Column: T-101B
Parameters
                                    Component            Mole Fraction
Light Key                           Ethanol                                              1.01E-02
Heavy Key                           1-Propanol                                           2.00E-02
Pressures (psia)                    Reflux Ratios
Condenser Pressure                                     20 External Reflux Ratio                               3.604
Reboiler Pressure                                      20 Minimum Reflux Ratio                                2.772
User Variables
Results Summary
Trays / Temperatures                Flows
Minimum # of Trays                               11.94 Rectify Vapour (lbmole/hr)                             115.1
Actual # of Trays                                23.76 Rectify Liquid (lbmole/hr)                             90.09
Optimal Feed Stage                               11.89 Stripping Vapour (lbmole/hr)                           115.1
Condenser Temperature (F)                        187.6 Stripping Liquid (lbmole/hr)                           164.8
Reboiler Temperature (F)                         221.6 Condenser Duty (Btu/hr)                           -1.88E+06
                                                       Reboiler Duty (Btu/hr)                             1.89E+06

    c. Using the design determined in ‘a’ and ‘b’, the MESH equations are solved using column
       in HYSYS.Plant. Note that minor adjustments in the the reflux ratios in both columns are
       made by the internal design specification to achieve the required component molar flow
       rates: In the first column, the reflux ratio is decreased from 2.298 to 2.192, while in the
       second column, it is reduced from 3.60 to 3.54.




Distillation: T-100C @Main
MONITOR
Specifications Summary               Specified Value      Current Value     Wt. Error        Wt. Tol.   Abs. Tol.        Active   E
Iso-prop in D                        49.50 lbmole/hr      49.50 lbmole/hr        2.62E-08      1.00E-02 2.205 lbmole/hr On        O
Iso-butanol in B                     9.800 lbmole/hr      9.800 lbmole/hr        1.39E-08      1.00E-02 2.205 lbmole/hr On        O
Distillate Rate                      74.70 lbmole/hr    74.70 lbmole/hr           5.28E-07     1.00E-02 2.205 lbmole/hr Off       O
Reflux Ratio                                      2.298            2.192         -4.61E-02     1.00E-02         1.00E-02 Off      O
Reflux Rate                                               163.7 lbmole/hr                      1.00E-02 2.205 lbmole/hr Off       O
Btms Prod Rate                                            25.30 lbmole/hr                      1.00E-02 2.205 lbmole/hr Off       O

                                                – 70 –
    Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

SPECS
Column Specification Parameters
Iso-prop in D
Draw: D1C                                 Flow Basis: Molar        Phase: Liquid
Components:                               1-Propanol
Iso-butanol in B
Draw: B1C                                 Flow Basis: Molar        Phase: Liquid
Components:                               i-Butanol
Distillate Rate
Stream: D1C                               Flow Basis: Molar
Reflux Ratio
Stage: Condenser                          Flow Basis: Molar        Liquid Specification:
Reflux Rate
Stage: Condenser                          Flow Basis: Molar        Liquid Specification:
Btms Prod Rate
Stream: B1C                               Flow Basis: Molar
User Variables
PROFILES
General Parameters
Sub-Flow Sheet: T-100C (COL1)             Number of Stages: 44


SOLVER
Column Solving Algorithm: HYSIM Inside-Out
Solving Options                           Acceleration Parameters
Maximum Iterations: 10000                 Accelerate K Value & H Model Parameters: Off
Equilibrium Error Tolerance: 1.000e-07
Heat/Spec Error Tolerance: 1.000e-007
Save Solutions as Initial Estimate: On
Super Critical Handling Model: Simple K
Trace Level: Low
Init from Ideal K's: Off                  Damping Parameters
Initial Estimate Generator Parameters     Azeotrope Check: Off
Iterative IEG (Good for Chemicals): Off   Fixed Damping Factor: 1


PROPERTIES

Properties : F3                           Overall                  Vapour Phase        Liquid Phase
Vapour/Phase Fraction                                         0                    0               1
Temperature: (F)                                          215.7                215.7           215.7
Pressure: (psia)                                             20                  20               20
Molar Flow (lbmole/hr)                                      100            5.12E-09              100
Mass Flow (lb/hr)                                          6010            2.85E-07             6010
Liquid Volume Flow (barrel/day)                           511.6            2.43E-08            511.6
Molar Enthalpy (Btu/lbmole)                           -1.24E+05                    0       -1.24E+05
Mass Enthalpy (Btu/lb)                                     -2065                   0            -2065
Molar Entropy (Btu/lbmole-F)                              13.49                    0           13.49
Mass Entropy (Btu/lb-F)                                  0.2245                    0          0.2245
Heat Flow (Btu/hr)                                    -1.24E+07                    0       -1.24E+07


                                                        – 71 –
    Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

Properties : D1C                              Overall                     Vapour Phase        Liquid Phase
Vapour/Phase Fraction                                                 0                   0               1
Temperature: (F)                                                  207.6               207.6           207.6
Pressure: (psia)                                                     20                  20              20
Molar Flow (lbmole/hr)                                             74.7                   0            74.7
Mass Flow (lb/hr)                                                  4141                   0            4141
Liquid Volume Flow (barrel/day)                                   353.7                   0           353.7
Molar Enthalpy (Btu/lbmole)                                -1.21E+05           -1.03E+05          -1.21E+05
Mass Enthalpy (Btu/lb)                                          -2188               -1947              -2188
Molar Entropy (Btu/lbmole-F)                                      9.962             34.28             9.962
Mass Entropy (Btu/lb-F)                                          0.1797            0.6464            0.1797
Heat Flow (Btu/hr)                                         -9.06E+06                      0       -9.06E+06


Properties : B1C                              Overall                     Vapour Phase        Liquid Phase
Vapour/Phase Fraction                                                0                    0                  1
Temperature: (F)                                                  251.5               251.5           251.5
Pressure: (psia)                                                    20                   20              20
Molar Flow (lbmole/hr)                                            25.3                    0            25.3
Mass Flow (lb/hr)                                                 1868                    0            1868
Liquid Volume Flow (barrel/day)                                 157.9                  0               157.9
Molar Enthalpy (Btu/lbmole)                                -1.31E+05           -1.15E+05          -1.31E+05
Mass Enthalpy (Btu/lb)                                           -1778                -1558           -1778
Molar Entropy (Btu/lbmole-F)                                     21.03                43.53           21.03
Mass Entropy (Btu/lb-F)                                        0.2848              0.5912             0.2848
Heat Flow (Btu/hr)                                         -3.32E+06                    0         -3.32E+06



Tray Summary
Flow Basis: Molar                                          Reflux Ratio: 2.192
                Temp.             Pressure        Liquid             Vapour           Feeds             Draws             Duties
                (F)               (psia)           (lbmole/hr)       (lbmole/hr)      (lbmole/hr)       (lbmole/hr)       (Btu/hr)
Condenser                 207.6              20              163.7                                               74.7 L    -3.98E+06
1__Main TS                  213              20              163.9            238.4
2__Main TS                215.7              20               164             238.6
3__Main TS                  217              20              164.1            238.7
4__Main TS                217.5              20              164.2            238.8
5__Main TS                217.8              20              164.2            238.9
6__Main TS                217.9              20              164.2            238.9
7__Main TS                  218              20              164.2            238.9
8__Main TS                218.1              20              164.2            238.9
9__Main TS                218.1              20              164.2            238.9
10__Main TS               218.2              20              164.2            238.9
11__Main TS               218.3              20              164.2            238.9
12__Main TS               218.4              20              164.2            238.9
13__Main TS               218.5              20              164.1            238.9
14__Main TS               218.6              20              164.1            238.8
15__Main TS               218.7              20              164.1            238.8
16__Main TS               218.9              20              164.1            238.8
17__Main TS                 219              20                164            238.8
                                                             – 72 –
    Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

18__Main TS          219.2         20            164        238.7
19__Main TS          219.5         20           163.9       238.7
20__Main TS          219.7         20           163.8       238.6
21__Main TS          220.1         20           163.7       238.5
22__Main TS          220.5         20           163.5       238.4
23__Main TS          221.1         20           163.3       238.2
24__Main TS          221.9         20             163         238
25__Main TS          222.9         20           263.7       237.7       100 L
26__Main TS            225         20           264.2       238.4
27__Main TS          226.3         20           264.5       238.9
28__Main TS          227.1         20           264.7       239.2
29__Main TS          227.8         20           264.8       239.4
30__Main TS          228.4         20           264.8       239.5
31__Main TS            229         20           264.8       239.5
32__Main TS          229.8         20           264.9       239.5
33__Main TS          230.7         20           264.9       239.6
34__Main TS          231.9         20           264.9       239.6
35__Main TS          233.3         20             265       239.6
36__Main TS          234.9         20           265.2       239.7
37__Main TS          236.6         20           265.3       239.9
38__Main TS          238.4         20           265.5         240
39__Main TS          240.3         20           265.6       240.2
40__Main TS          242.2         20           265.7       240.3
41__Main TS            244         20           265.6       240.4
42__Main TS          245.9         20           265.4       240.3
43__Main TS          247.7         20           265.1       240.1
44__Main TS          249.6         20           264.7       239.8
Reboiler             251.5         20                       239.4                    25.3 L    4.01E+06




                                               – 73 –
Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

  Distillation: T-101C @Main



  MONITOR
  Specifications Summary
                                            Specified Value         Current Value   Wt. Error    Wt. Tol.  Abs. Tol.       Ab
  Ethanol in D                              24.50 lbmole/hr         24.50 lbmole/hr      5.99E-09 1.00E-02 2.205 lbmole/hr 2.2
  Iso-propanol in B                         49.00 lbmole/hr         49.00 lbmole/hr         -1.58E-08   1.00E-02 2.205 lbmole/hr 2.2
  Distillate Rate                           25.00 lbmole/hr         25.00 lbmole/hr          5.68E-07   1.00E-02 2.205 lbmole/hr 2.2
  Reflux Ratio                                                3.6              3.537        -1.75E-02   1.00E-02         1.00E-02
  Reflux Rate                                                       88.43 lbmole/hr                     1.00E-02 2.205 lbmole/hr 2.2
  Btms Prod Rate                                                    49.70 lbmole/hr                     1.00E-02 2.205 lbmole/hr 2.2
  SPECS
  Column Specification Parameters
  Ethanol in D
  Draw: D2C @COL2                           Flow Basis: Molar       Phase: Liquid
  Components:                               Ethanol
  Iso-propanol in B
  Draw: B2C @COL2                           Flow Basis: Molar       Phase: Liquid
  Components:                               1-Propanol
  Distillate Rate
  Stream: D2C @COL2                         Flow Basis: Molar
  Reflux Ratio
  Stage: Condenser                          Flow Basis: Molar       Liquid Specification:
  Reflux Rate
  Stage: Condenser                          Flow Basis: Molar       Liquid Specification:
  Btms Prod Rate
  Stream: B2C @COL2                         Flow Basis: Molar
  User Variables
  PROFILES
  General Parameters
  Sub-Flow Sheet: T-101C (COL2)             Number of Stages: 24


  SOLVER
  Column Solving Algorithm: HYSIM Inside-Out
  Solving Options                           Acceleration Parameters
  Maximum Iterations: 10000                 Accelerate K Value & H Model Parameters: Off
  Equilibrium Error Tolerance: 1.000e-07
  Heat/Spec Error Tolerance: 1.000e-007
  Save Solutions as Initial Estimate: On
  Super Critical Handling Model: Simple K
  Trace Level: Low
  Init from Ideal K's: Off                  Damping Parameters
  Initial Estimate Generator Parameters     Azeotrope Check: Off
  Iterative IEG (Good for Chemicals): Off   Fixed Damping Factor: 1


  PROPERTIES
  Properties : D1C @COL2                    Overall                 Liquid Phase
  Vapour/Phase Fraction                                         0                     1
                                                – 74 –
    Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

      Temperature: (F)                                                207.6                207.6
      Pressure: (psia)                                                   20                   20
      Molar Flow (lbmole/hr)                                           74.7                 74.7
      Mass Flow (lb/hr)                                                4141                 4141
      Liquid Volume Flow (barrel/day)                                 353.7                353.7
      Molar Enthalpy (Btu/lbmole)                                -1.21E+05            -1.21E+05
      Mass Enthalpy (Btu/lb)                                          -2188                -2188
      Molar Entropy (Btu/lbmole-F)                                    9.962                9.962
      Mass Entropy (Btu/lb-F)                                        0.1797               0.1797
      Heat Flow (Btu/hr)                                         -9.06E+06            -9.06E+06

      Properties : D2C @COL2                           Overall                  Vapour Phase         Liquid Phase
      Vapour/Phase Fraction                                                 0                   0                   1
      Temperature: (F)                                                187.6                187.6              187.6
      Pressure: (psia)                                                   20                   20                 20
      Molar Flow (lbmole/hr)                                            25                      0               25
      Mass Flow (lb/hr)                                               1159                      0             1159
      Liquid Volume Flow (barrel/day)                                 99.65                   0               99.65
      Molar Enthalpy (Btu/lbmole)                                -1.16E+05            -9.94E+04          -1.16E+05
      Mass Enthalpy (Btu/lb)                                         -2498                 -2152              -2498
      Molar Entropy (Btu/lbmole-F)                                   5.864                 30.95              5.864
      Mass Entropy (Btu/lb-F)                                        0.1265               0.6698             0.1265
      Heat Flow (Btu/hr)                                         -2.90E+06                     0         -2.90E+06


      Properties : B2C @COL2                           Overall                  Vapour Phase         Liquid Phase
      Vapour/Phase Fraction                                               0                    0                  1
      Temperature: (F)                                                221.6                221.6              221.6
      Pressure: (psia)                                                   20                     20               20
      Molar Flow (lbmole/hr)                                           49.7                      0             49.7
      Mass Flow (lb/hr)                                               2983                      0             2983
      Liquid Volume Flow (barrel/day)                                  254                      0              254
      Molar Enthalpy (Btu/lbmole)                                -1.24E+05            -1.07E+05          -1.24E+05
      Mass Enthalpy (Btu/lb)                                          -2062                -1789              -2062
      Molar Entropy (Btu/lbmole-F)                                     10.7                35.11               10.7
      Mass Entropy (Btu/lb-F)                                        0.1783               0.5865            0.1783
      Heat Flow (Btu/hr)                                         -6.15E+06                      0        -6.15E+06

Tray Summary
Flow Basis: Molar     Reflux Ratio: 3.537
                      Temp.    Pressure Liquid                   Vapour           Feeds         Feeds          Draws             Duties
                         (F)           (psia)      (lbmole/hr) (lbmole/hr)        (lbmole/hr)   (lbmole/hr)     (lbmole/hr)      (Btu/hr)
Condenser                      187.6            20        88.43                                                           25 L   -1.85E+06
1__Main TS                     188.1            20        88.3            113.4
2__Main TS                       189            20       88.11            113.3
3__Main TS                     190.2            20       87.86            113.1
4__Main TS                       192            20       87.54            112.9
5__Main TS                     194.2            20       87.19            112.5
6__Main TS                     196.9            20       86.87            112.2
7__Main TS                     199.7            20       86.61            111.9

                                                            – 75 –
    Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

8__Main TS              202.3       20       86.45       111.6
9__Main TS              204.6       20       86.36       111.4
10__Main TS             206.3       20       86.32       111.4
11__Main TS             207.5       20        86.3       111.3
12__Main TS             208.4       20        161        111.3        74.7       75.7
13__Main TS             209.4       20         161       111.3
14__Main TS             210.6       20         161       111.3
15__Main TS             211.9       20       161.1       111.3
16__Main TS             213.4       20       161.1       111.4
17__Main TS             214.8       20       161.2       111.4
18__Main TS             216.2       20       161.3       111.5
19__Main TS             217.5       20       161.5       111.6
20__Main TS             218.6       20       161.6       111.8
21__Main TS             219.5       20       161.7       111.9
22__Main TS             220.2       20       161.8         112
23__Main TS             220.8       20       161.9       112.1
24__Main TS             221.3       20       161.9       112.2
Reboiler                221.6       20                   112.2                               49.7 L   1.86E+06




                                               – 76 –
     Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                           Exercise D.1 Solution using ASPEN.PLUS

       Based upon the specifications, the desired product streams are determined by material
balance:

                             FEED        DIS1      BOT1     DIS2     BOT2
                 EtOH          25.0       25.0         -     24.5      0.5
                 nPOH          50.0       49.5       0.5      0.5     49.0
                 iBOH          10.0        0.2       9.8        -      0.2
                 nBOH          15.0           -     15.0        -        -
                   Total      100.0       74.7      25.3     25.0     49.7

a.                  The column pressures are determined using the SEP2 subroutine in ASPEN
                    PLUS with design specifications that adjust the distillate pressure to achieve
                    distillate bubble points at 130°F. The lower bound of 20 psia to avoid vacuum
                    operation. Note that because the most volatile species, ethanol, is present in the
                    distillate of both towers, the pressure is adjusted to its lower bound in both
                    towers. The results below can be reproduced using the file SEP2.BKP.

                                                                      DIS2

                                                  DIS1




                                             D1                       D2
                             FEED




                                      BOT1



                                                                      BOT2



       ASPEN PLUS Program

           TITLE 'PRESSURE DETERMINATION'
           IN-UNITS ENG
           DEF-STREAMS CONVEN ALL
           DESCRIPTION "
             General Simulation with English Units :
             F, psi, lb/hr, lbmol/hr, Btu/hr, cuft/hr.
             Property Method: None
             Flow basis for input: Mole
             Stream report composition: Mole flow
           DATABANKS PURE11 / AQUEOUS / SOLIDS / INORGANIC / &
                NOASPENPCD
           PROP-SOURCES PURE11 / AQUEOUS / SOLIDS / INORGANIC
           COMPONENTS
             ETHANOL C2H6O-2 /
             PROPANOL C3H8O-1 /
             ISOBU-01 C4H10O-3 /

                                                   – 77 –
  Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

          N-BUT-01 C4H10O-1
        FLOWSHEET
          BLOCK D1 IN=FEED OUT=DIS1 BOT1
          BLOCK D2 IN=DIS1 OUT=DIS2 BOT2
        PROPERTIES IDEAL
        STREAM FEED
          SUBSTREAM MIXED PRES=20. <psia> VFRAC=0. MOLE-FLOW=100.
          MOLE-FRAC ETHANOL 0.25 / PROPANOL 0.5 / ISOBU-01 0.1 / &
            N-BUT-01 0.15
        BLOCK D1 SEP2
          FRAC STREAM=DIS1 SUBSTREAM=MIXED COMPS=ETHANOL PROPANOL &
            ISOBU-01 N-BUT-01 FRACS=1. 0.99 0.02 0.
          FLASH-SPECS DIS1 PRES=20. VFRAC=0.
          FLASH-SPECS BOT1 PRES=20. VFRAC=0.
        BLOCK D2 SEP2
          FRAC STREAM=DIS2 SUBSTREAM=MIXED COMPS=ETHANOL PROPANOL &
            ISOBU-01 N-BUT-01 FRACS=0.98 0.0101 0. 0.
          FLASH-SPECS DIS2 PRES=20. VFRAC=0.
          FLASH-SPECS BOT2 PRES=20. VFRAC=0.
        DESIGN-SPEC DS-1
          DEFINE DIS1T STREAM-VAR STREAM=DIS1 SUBSTREAM=MIXED &
            VARIABLE=TEMP
          SPEC "DIS1T" TO "130"
          TOL-SPEC "0.001"
          VARY BLOCK-VAR BLOCK=D1 VARIABLE=PRES SENTENCE=FLASH-SPECS &
            ID1=DIS1
          LIMITS "20" "100"
        DESIGN-SPEC DS-2
          DEFINE DIS2T STREAM-VAR STREAM=DIS2 SUBSTREAM=MIXED &
            VARIABLE=TEMP
          SPEC "DIS2T" TO "130"
          TOL-SPEC "0.001"
          VARY BLOCK-VAR BLOCK=D2 VARIABLE=PRES SENTENCE=FLASH-SPECS &
            ID1=DIS2
          LIMITS "20" "100"
        EO-CONV-OPTI
        STREAM-REPOR MOLEFLOW

    Stream Variables
BOT1 BOT2 DIS1 DIS2 FEED
------------------------

STREAM ID                  BOT1         BOT2            DIS1       DIS2        FEED
FROM :                     D1           D2              D1         D2          ----
TO   :                     ----         ----            D2         ----        D1
SUBSTREAM: MIXED
PHASE:                     LIQUID       LIQUID          LIQUID      LIQUID      LIQUID
COMPONENTS: LBMOL/HR
  ETHANOL                   0.0          0.5000         25.0000     24.5000     25.0000
  PROPANOL                  0.5000      49.0001         49.5000      0.5000     50.0000
  ISOBU-01                  9.8000       0.2000          0.2000      0.0        10.0000
  N-BUT-01                 15.0000       0.0             0.0         0.0        15.0000
TOTAL FLOW:
  LBMOL/HR                 25.3000     49.7001       74.7000        25.0000    100.0000
  LB/HR                  1868.2934   2982.5622     4141.2986      1158.7364   6009.5920
  CUFT/HR                  42.3597     65.9918       92.2460        26.5987    133.8460

STATE VARIABLES:
  TEMP    F               251.0983     221.6330     207.8053      187.9351    215.8258
  PRES    PSI              20.0000      20.0000      20.0000       20.0000     20.0000
  VFRAC                     0.0          0.0          0.0           0.0         0.0
  LFRAC                     1.0000       1.0000       1.0000        1.0000      1.0000
  SFRAC                     0.0          0.0          0.0           0.0         0.0
ENTHALPY:
  BTU/LBMOL            -1.3208+05 -1.2398+05 -1.2143+05 -1.1582+05 -1.2441+05
                                               – 78 –
     Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

   BTU/LB                 -1788.6308 -2066.0146 -2190.2920 -2498.7500 -2070.2178
   BTU/HR                 -3.3417+06 -6.1620+06 -9.0707+06 -2.8954+06 -1.2441+07
 ENTROPY:
   BTU/LBMOL-R              -116.3746     -97.0906     -89.4718      -76.9346   -95.6280
   BTU/LB-R                   -1.5759      -1.6179      -1.6139       -1.6599    -1.5913
 DENSITY:
   LBMOL/CUFT                  0.5973       0.7531          0.8098     0.9399      0.7471
   LB/CUFT                    44.1054      45.1959         44.8941    43.5637     44.8993
 AVG MW                       73.8456      60.0113         55.4391    46.3496     60.0959


b.                  Using the tower pressures determined in ‘a’, the numbers of trays and the
                    reflux ratios are determined using the DSTWU subroutine in ASPEN PLUS,
                    for splits specified to give the desired products. The towers have 41 and 23
                    stages and reflux ratios of 2.39 and 3.64. The results below can be reproduced
                    using the file DSTWU.BKP.

                    ASPEN PLUS Program – paragraphs that differ from above.

           TITLE 'DESIGN CALCULATIONS'

           BLOCK D1 DSTWU
             PARAM LIGHTKEY=1-PRO-01 RECOVL=0.99 HEAVYKEY=ISOBU-01 &
               RECOVH=0.02 PTOP=20. PBOT=20. RDV=0.0 RR=-1.3

           BLOCK D2 DSTWU
             PARAM LIGHTKEY=ETHAN-01 RECOVL=0.98 HEAVYKEY=1-PRO-01 &
               RECOVH=0.0101 PTOP=20. PBOT=20. RR=-1.3

                    Selected Process Unit Output
BLOCK: D1        MODEL: DSTWU
 -----------------------------

                            *** INPUT DATA           ***
     HEAVY KEY COMPONENT                                                    ISOBU-01
     RECOVERY FOR HEAVY KEY                                             0.020000
     LIGHT KEY COMPONENT                                                   1-PRO-01
     RECOVERY FOR LIGHT KEY                                             0.99000
     TOP STAGE PRESSURE (PSI     )                                     20.0000
     BOTTOM STAGE PRESSURE (PSI     )                                  20.0000
     REFLUX RATIO                                                      -1.30000
     DISTILLATE VAPOR FRACTION                                          0.0

                            *** RESULTS ***
     DISTILLATE TEMP. (F        )                                     207.805
     BOTTOM TEMP. (F        )                                         251.098
     MINIMUM REFLUX RATIO                                               1.83652
     ACTUAL REFLUX RATIO                                                2.38747
     MINIMUM STAGES                                                    22.2947
     ACTUAL EQUILIBRIUM STAGES                                         40.9995
     NUMBER OF ACTUAL STAGES ABOVE FEED                                18.5858
     DIST. VS FEED                                                      0.74700
     CONDENSER COOLING REQUIRED (BTU/HR )                       4,381,070.
     NET CONDENSER DUTY (BTU/HR )                              -4,381,070.
     REBOILER HEATING REQUIRED (BTU/HR )                        4,409,900.
     NET REBOILER DUTY (BTU/HR )                                4,409,900.


 BLOCK: D2        MODEL: DSTWU
 -----------------------------
                               ***   INPUT DATA      ***
     HEAVY KEY COMPONENT                                                    1-PRO-01
     RECOVERY FOR HEAVY KEY                                              0.010100
     LIGHT KEY COMPONENT                                                    ETHAN-01
     RECOVERY FOR LIGHT KEY                                              0.98000
                                                – 79 –
     Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

     TOP STAGE PRESSURE (PSI           )                                 20.0000
     BOTTOM STAGE PRESSURE (PSI            )                             20.0000
     REFLUX RATIO                                                        -1.30000
     DISTILLATE VAPOR FRACTION                                            0.0
                            *** RESULTS ***
     DISTILLATE TEMP. (F        )                                        187.935
     BOTTOM TEMP. (F        )                                            221.633
     MINIMUM REFLUX RATIO                                                  2.80216
     ACTUAL REFLUX RATIO                                                   3.64280
     MINIMUM STAGES                                                       12.1016
     ACTUAL EQUILIBRIUM STAGES                                            22.2106
     NUMBER OF ACTUAL STAGES ABOVE FEED                                   11.6852
     DIST. VS FEED                                                         0.33467
     CONDENSER COOLING REQUIRED (BTU/HR )                          1,918,790.
     NET CONDENSER DUTY (BTU/HR )                                 -1,918,790.
     REBOILER HEATING REQUIRED (BTU/HR )                           1,932,040.
     NET REBOILER DUTY (BTU/HR )                                   1,932,040.


c.                  Using the design determined in ‘a’ and ‘b’, the MESH equations are solved
                    using the RADFRAC subroutine in ASPEN PLUS. The results below can be
                    reproduced using the file RADFRAC.BKP. Note that the reflux ratio in the
                    second column is increased using an internal design specification to achieve a
                    molar flow rate of
                    n-pentanol in the distillate of 0.5 lbmole/hr. The reflux ratio is increased from
                    3.64 to 4.28.


                    ASPEN PLUS Program – paragraphs that differ from above.

           TITLE 'RADFRAC SIMULATION'

           BLOCK D1 RADFRAC
             PARAM NSTAGE=41
             COL-CONFIG CONDENSER=TOTAL
             FEEDS FEED 19
             PRODUCTS DIS1 1 L / BOT1 41 L
             P-SPEC 1 20.
             COL-SPECS DP-COL=0. MOLE-D=74.7 MOLE-RR=3.65
             SC-REFLUX DEGSUB=0.

           BLOCK D2 RADFRAC
             PARAM NSTAGE=23
             COL-CONFIG CONDENSER=TOTAL
             FEEDS DIS1 12
             PRODUCTS DIS2 1 L / BOT2 23 L
             P-SPEC 1 20.
             COL-SPECS DP-COL=0. MOLE-D=25. MOLE-RR=3.64
             SC-REFLUX DEGSUB=0.
             SPEC 1 MOLE-FLOW 0.5 COMPS=1-PRO-01 STREAMS=DIS2
             VARY 1 MOLE-RR 3.6 8.



                    Stream Variables
BOT1 BOT2 DIS1 DIS2 FEED
 ------------------------
 STREAM ID                BOT1             BOT2            DIS1        DIS2          FEED
 FROM :                   D1               D2              D1          D2            ----
 TO   :                   ----             ----            D2          ----          D1


                                                  – 80 –
      Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

 SUBSTREAM: MIXED
 PHASE:                  LIQUID     LIQUID     LIQUID     LIQUID     LIQUID
 COMPONENTS: LBMOL/HR
   ETHAN-01            1.7690-08     0.5000    25.0000    24.5000    25.0000
   1-PRO-01               0.3762    49.1238    49.6238     0.5000    50.0000
   ISOBU-01               9.9239 7.6048-02 7.6055-02 6.6135-06       10.0000
   N-BUT-01              14.9999 1.1262-04 1.1262-04 1.2194-10       15.0000
 TOTAL FLOW:
   LBMOL/HR              25.3000    49.7000    74.7000    25.0000   100.0000
   LB/HR               1870.0304 2980.8221 4139.5616 1158.7395 6009.5920
   CUFT/HR               42.4066    65.9498    92.2053    26.5987   133.8460
 STATE VARIABLES:
   TEMP    F            251.2361   221.5931   207.7846   187.9348   215.8258
   PRES    PSI           20.0000    20.0000    20.0000    20.0000    20.0000
   VFRAC                  0.0        0.0        0.0        0.0        0.0
   LFRAC                  1.0000     1.0000     1.0000     1.0000     1.0000
   SFRAC                  0.0        0.0        0.0        0.0        0.0
 ENTHALPY:
   BTU/LBMOL          -1.3213+05 -1.2396+05 -1.2141+05 -1.1582+05 -1.2441+05
   BTU/LB             -1787.5949 -2066.7655 -2190.8725 -2498.7491 -2070.2178
   BTU/HR             -3.3429+06 -6.1607+06 -9.0693+06 -2.8954+06 -1.2441+07
 ENTROPY:
   BTU/LBMOL-R         -116.5121   -97.0604   -89.4507   -76.9346   -95.6280
   BTU/LB-R              -1.5763    -1.6183    -1.6142    -1.6599    -1.5913
 DENSITY:
   LBMOL/CUFT             0.5966     0.7536     0.8101     0.9399     0.7471
   LB/CUFT               44.0976    45.1983    44.8951    43.5637    44.8993
 AVG MW                  73.9142    59.9763    55.4158    46.3496    60.0959


                     Selected Process Unit Output
BLOCK: D1        MODEL: RADFRAC
 -------------------------------
    INLETS   - FEED     STAGE 19
    OUTLETS - DIS1      STAGE    1
               BOT1     STAGE 41

         ****    COL-SPECS     ****

      MOLAR VAPOR DIST / TOTAL DIST                                      0.0
      MOLAR REFLUX RATIO                                                 3.65000
      MOLAR DISTILLATE RATE                LBMOL/HR                     74.7000
      DIST + REFLUX DEG SUBCOOLED          F                             0.0


***      COMPONENT SPLIT FRACTIONS        ***
                                  OUTLET STREAMS
                                   --------------
                       DIS1          BOT1
      COMPONENT:
      ETHAN-01      1.0000            .70758E-09
      1-PRO-01      .99248            .75233E-02
      ISOBU-01      .76055E-02        .99239
      N-BUT-01      .75079E-05        .99999



***       SUMMARY OF KEY RESULTS         ***
      TOP STAGE TEMPERATURE                F                         207.785
      BOTTOM STAGE TEMPERATURE             F                         251.236
      TOP STAGE LIQUID FLOW                LBMOL/HR                  272.655
      BOTTOM STAGE LIQUID FLOW             LBMOL/HR                   25.3000
      TOP STAGE VAPOR FLOW                 LBMOL/HR                    0.0
      BOTTOM STAGE VAPOR FLOW              LBMOL/HR                  339.834
      MOLAR REFLUX RATIO                                               3.65000
      MOLAR BOILUP RATIO                                              13.4322
      CONDENSER DUTY (W/O SUBCOOL)         BTU/HR             -6,046,320.
      REBOILER DUTY                        BTU/HR              6,075,370.
      DIST + REFLUX SUBCOOLED TEMP         F                         207.785
                                                   – 81 –
                       Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                        SUBCOOLED REFLUX DUTY                       BTU/HR                                          0.0
                                                                              ENTHALPY
 STAGE TEMPERATURE                          PRESSURE                         BTU/LBMOL                              HEAT DUTY
       F                                    PSI                        LIQUID        VAPOR                           BTU/HR
   1                          207.78        20.000             -0.12141E+06                      -0.10277E+06      -.60463+07
 SUBC                         207.78        20.000             -0.12141E+06
   2                          213.04        20.000             -0.12249E+06                      -0.10400E+06
   3                          216.05        20.000             -0.12305E+06                      -0.10477E+06
  17                          220.75        20.000             -0.12449E+06                      -0.10608E+06
  18                          221.49        20.000             -0.12477E+06                      -0.10622E+06
  19                          222.55        20.000             -0.12513E+06                      -0.10641E+06
  20                          224.14        20.000             -0.12542E+06                      -0.10690E+06
  40                          249.40        20.000             -0.13235E+06                      -0.11469E+06
  41                          251.24        20.000             -0.13213E+06                      -0.11449E+06       .60754+07
 STAGE      FLOW RATE                                                       FEED RATE                                PRODUCT RATE
             LBMOL/HR                                                        LBMOL/HR                                  LBMOL/HR
       LIQUID      VAPOR                                LIQUID                VAPOR                   MIXED        LIQUID    VAPOR
   1 272.7       0.0000E+00
 SUBC 272.7                                                                                                         74.7000
   2 271.1        347.4
   3 270.5        345.8
  17 268.9        344.0
  18 268.4        343.6                                                     .20341-03
  19 368.2        343.1                                 99.9998
  20 368.1        342.9
  40 365.1        340.5
  41 25.30        339.8                                                                                             25.3000

                                                             Block D1: Liquid Composition Profiles
                 1




                                                                                                                                ETHAN-01
                                                                                                                                1-PRO-01
                                                                                                                                ISOBU-01
                                                                                                                                N-BUT-01
                 0.8
                 0.6
 X (mole frac)
                 0.4
                 0.2




                   1              6         11          16                    21                     26       31          36               41
                                                                            Stage




BLOCK: D2        MODEL: RADFRAC
 -------------------------------
    INLETS   - DIS1     STAGE 12
    OUTLETS - DIS2      STAGE    1
               BOT2     STAGE 23
                       ****     COL-SPECS        ****

                        MOLAR VAPOR DIST / TOTAL DIST                                                               0.0
                        MOLAR REFLUX RATIO                                                                          3.64000
                        MOLAR DISTILLATE RATE                       LBMOL/HR                                       25.0000
                        DIST + REFLUX DEG SUBCOOLED                 F                                               0.0


                                                                                    – 82 –
  Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

  ***     COMPONENT SPLIT FRACTIONS        ***
                                 OUTLET STREAMS
                                 --------------
                    DIS2           BOT2
   COMPONENT:
   ETHAN-01      .98000          .20000E-01
   1-PRO-01      .10076E-01      .98992
   ISOBU-01      .86957E-04      .99991
   N-BUT-01      .10828E-05      1.0000


  ***      SUMMARY OF KEY RESULTS       ***
   TOP STAGE TEMPERATURE               F                             187.935
   BOTTOM STAGE TEMPERATURE            F                             221.593
   TOP STAGE LIQUID FLOW               LBMOL/HR                      107.050
   BOTTOM STAGE LIQUID FLOW            LBMOL/HR                       49.7000
   TOP STAGE VAPOR FLOW                LBMOL/HR                        0.0
   BOTTOM STAGE VAPOR FLOW             LBMOL/HR                      124.782
   MOLAR REFLUX RATIO                                                  4.28199
   MOLAR BOILUP RATIO                                                  2.51071
   CONDENSER DUTY (W/O SUBCOOL)        BTU/HR                 -2,180,430.
   REBOILER DUTY                       BTU/HR                  2,193,610.
   DIST + REFLUX SUBCOOLED TEMP        F                             187.935
   SUBCOOLED REFLUX DUTY               BTU/HR                          7.60648



                                                 ENTHALPY
STAGE TEMPERATURE     PRESSURE                  BTU/LBMOL              HEAT DUTY
      F               PSI                 LIQUID        VAPOR           BTU/HR
  1     187.93        20.000        -0.11582E+06          -99230.    -.21804+07
SUBC    187.93        20.000        -0.11582E+06                         7.6064
  2     188.46        20.000        -0.11600E+06       -99304.
  3     189.31        20.000        -0.11630E+06       -99424.
 10     206.29        20.000        -0.12107E+06      -0.10245E+06
 11     208.05        20.000        -0.12146E+06      -0.10283E+06
 12     209.28        20.000        -0.12173E+06      -0.10311E+06
 13     210.82        20.000        -0.12204E+06      -0.10346E+06
 22     221.26        20.000        -0.12390E+06      -0.10620E+06
 23     221.59        20.000        -0.12396E+06      -0.10630E+06    .21936+07

STAGE      FLOW RATE                        FEED RATE                  PRODUCT RATE
            LBMOL/HR                         LBMOL/HR                    LBMOL/HR
      LIQUID      VAPOR          LIQUID       VAPOR         MIXED    LIQUID    VAPOR
  1 107.0       0.0000E+00
SUBC 107.0                                                             25.0000
  2 106.8        132.0
  3 106.4        131.8
 10 101.7        127.1
 11 101.5        126.7                      .89755-05
 12 175.9        126.5           74.6999
 13 175.6        126.2
 22 174.5        124.8
 23 49.70        124.8                                                 49.7000




                                                 – 83 –
                      Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                                                        Block D2: Liquid Composition Profiles


                1
                0.8




                                                                                                               ETHAN-01
                                                                                                               1-PRO-01
                                                                                                               ISOBU-01
                                                                                                               N-BUT-01
                0.6
X (mole frac)
                0.4
                0.2




                  1          3      5       7       9            11               13            15   17   19              21   23
                                                                       Stage




                                                                               – 84 –
     Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                             Exercise D.2 Solution using HYSYS.Plant

                            Solution reproduced in: DISTIL_EX_2.hsc

       Based upon the specifications, the desired product streams (in kgmol/hr) are determined
by material balance:

                                              FEED       D1          B1
                               Benzene          12.5      12.50         -
                               Toluene          22.5     22.275    0.2250
                              o-Xylene          37.5     0.2250    37.275
                             n-PBenzene         27.5          -     27.50
                                 Total         100.0      35.00     65.00

a.                  In HYSYS.Plant, the column pressures are determined using the Component
                    Splitter, adjusting the distillate pressure to achieve distillate bubble points at
                    50°C, with lower bounds of 20 psia to avoid vacuum operation. Note that due
                    to volatiles in the overhead, the column pressure is dictated by this lower
                    bound.




Component Splitter: X-100

PARAMETERS
Stream Specifications
Overhead Pressure: 20.00 psia                 Overhead Vapor Fraction: 0.00
Bottoms Pressure: 20.00 psia                  Bottoms Vapor Fraction: 0.00
SPLITS
Component Fraction To Overhead
Component                                     Overhead Fraction
Benzene                                                                      1
Toluene                                                                   0.99
PROPERTIES



                                                – 85 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course


F1                                          Overall                            Liquid Phase         Vapor Phase
Vapour/Phase Fraction                                                     0                    1                  0
Temperature: (C)                                                      134.6                134.6              134.6
Pressure: (psig)                                                      5.304                5.304              5.304
Molar Flow (kgmole/h)                                                   100                  100                  0
Mass Flow (kg/h)                                                  1.03E+04             1.03E+04                   0
Liquid Volume Flow (m3/h)                                             11.82                11.82                  0
Molar Enthalpy (kJ/kgmole)                                        1.06E+04             1.06E+04           6.41E+04
Mass Enthalpy (J/kg)                                              1.03E+05             1.03E+05           6.88E+05
Molar Entropy (kJ/gmole-C)                                        3.66E-02             3.66E-02           6.85E-02
Mass Entropy (kJ/g-C)                                             3.54E-04             3.54E-04           7.35E-04
Heat Flow (kJ/h)                                                  1.06E+06             1.06E+06                   0

D1                                          Overall                            Liquid Phase         Vapor Phase
Vapour/Phase Fraction                                                     0                    1                  0
Temperature: (C)                                                      107.7                107.7              107.7
Pressure: (psig)                                                      5.304                5.304              5.304
Molar Flow (kgmole/h)                                                    35                   35                  0
Mass Flow (kg/h)                                                       3053                 3053                  0
Liquid Volume Flow (m3/h)                                             3.493                3.493                  0
Molar Enthalpy (kJ/kgmole)                                        3.81E+04             3.81E+04           7.68E+04
Mass Enthalpy (J/kg)                                              4.37E+05             4.37E+05           9.11E+05
Molar Entropy (kJ/gmole-C)                                        -7.86E-02            -7.86E-02          -5.09E-03
Mass Entropy (kJ/g-C)                                             -9.01E-04            -9.01E-04          -6.04E-05
Heat Flow (kJ/h)                                                  1.33E+06             1.33E+06                   0

B1                                          Overall                            Liquid Phase         Vapor Phase
Vapour/Phase Fraction                                                      0                    1                 0
Temperature: (C)                                                       161.4                161.4             161.4
Pressure: (psig)                                                       5.304                5.304             5.304
Molar Flow (kgmole/h)                                                     65                   65                 0
Mass Flow (kg/h)                                                        7283                 7283                 0
Liquid Volume Flow (m3/h)                                              8.327                8.327                 0
Molar Enthalpy (kJ/kgmole)                                            -261.3               -261.3         3.76E+04
Mass Enthalpy (J/kg)                                                   -2332                -2332         3.39E+05
Molar Entropy (kJ/gmole-C)                                         9.96E-02             9.96E-02             0.1951
Mass Entropy (kJ/g-C)                                              8.89E-04             8.89E-04          1.76E-03
Heat Flow (kJ/h)                                                  -1.70E+04            -1.70E+04                  0



   d. Using the tower pressures determined in ‘a’, the numbers of trays and the reflux ratios are
      determined using short-cut column in HYSYS.Plant, for splits specified to give the
      desired products. The minimum number of trays is 13. For 1.3Rmin, the design calls for
      26 trays, with feed entering on the 13th tray, with a reflux ratio of 2.206.




                                              – 86 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course




Shortcut Column: T-100

                            Component                    Mole Fraction
Light Key                   Toluene                                               3.46E-03
Heavy Key                   o-Xylene                                              6.43E-03
Pressures (psig)            Reflux Ratios
Condenser Pressure                                     20 External Reflux Ratio                         2.206
Reboiler Pressure                                      20 Minimum Reflux Ratio                          1.697
User Variables
Results Summary
Trays / Temperatures        Flows
Minimum # of Trays                                12.63 Rectify Vapour (kgmole/h)                        112.2
Actual # of Trays                                  26.1 Rectify Liquid (kgmole/h)                        77.21
Optimal Feed Stage                                 12.9 Stripping Vapour (kgmole/h)                      112.2
Condenser Temperature (C)                         129.3 Stripping Liquid (kgmole/h)                      177.2
Reboiler Temperature (C)                          185.2 Condenser Duty (kJ/h)                       -3.57E+06
                                                        Reboiler Duty (kJ/h)                         3.82E+06

   e. Using the design determined in ‘a’ and ‘b’, the MESH equations are solved using column
      in HYSYS.Plant. Note that a minor adjustment in the reflux ratio is made by the internal
      design specification to achieve the required component molar flow rates: 2.206 to 2.49.




                                              – 87 –
    Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course


Distillation: T-101

MONITOR

Specifications Summary
                         Specified Value     Current Value       Wt. Error    Wt. Tol.  Abs. Tol.   Active Estimate
Toluene Recovery                        0.99                0.99     1.06E-08 1.00E-02        1.00E-03 On    On
Xylene Recovery                        0.994               0.994     8.59E-10 1.00E-02        1.00E-03 On    On
Distillate Rate          35.00 kgmole/h      35.00 kgmole/h          3.36E-05 1.00E-02 1.000 kgmole/h Off    On
Reflux Ratio                           2.206               2.493          0.13 1.00E-02       1.00E-02 Off   On
Reflux Rate                                  87.25 kgmole/h                    1.00E-02 1.000 kgmole/h Off   On
Btms Prod Rate                               65.00 kgmole/h                    1.00E-02 1.000 kgmole/h Off   On

SPECS
Column Specification Parameters
Toluene Recovery
Draw: D3 @COL1                        Flow Basis: Molar
Components:                           Toluene
Xylene Recovery
Draw: B3 @COL1                        Flow Basis: Molar
Components:                           o-Xylene
Distillate Rate
Stream: D3 @COL1                      Flow Basis: Molar


Reflux Ratio
Stage: Condenser                      Flow Basis: Molar         Liquid Specification:
Reflux Rate
Stage: Condenser                      Flow Basis: Molar         Liquid Specification:
Btms Prod Rate
Stream: B3 @COL1                      Flow Basis: Molar
User Variables
PROFILES
General Parameters
Sub-Flow Sheet: T-101 (COL1)          Number of Stages: 26

SOLVER
Column Solving Algorithm: HYSIM Inside-Out
Solving Options                                 Acceleration Parameters
Maximum Iterations: 10000                       Accelerate K Value & H Model Parameters: Off
Equilibrium Error Tolerance: 1.000e-07
Heat/Spec Error Tolerance: 1.000e-007
Save Solutions as Initial Estimate: On
Super Critical Handling Model: Simple K
Trace Level: Low
Init from Ideal K's: Off                        Damping Parameters
Initial Estimate Generator Parameters           Azeotrope Check: Off
Iterative IEG (Good for Chemicals): Off         Fixed Damping Factor: 1


                                               – 88 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course


PROPERTIES
Properties : F3 @COL1
                                  Overall                Liquid Phase
Vapour/Phase Fraction                                0                     1
Temperature: (C)                                 158.2                 158.2
Pressure: (psig)                                    20                    20
Molar Flow (kgmole/h)                              100                   100
Mass Flow (kg/h)                             1.03E+04              1.03E+04
Liquid Volume Flow (m3/h)                        11.82                 11.82
Molar Enthalpy (kJ/kgmole)                   1.59E+04              1.59E+04
Mass Enthalpy (J/kg)                         1.54E+05              1.54E+05
Molar Entropy (kJ/gmole-C)                   4.92E-02              4.92E-02
Mass Entropy (kJ/g-C)                        4.76E-04              4.76E-04
Heat Flow (kJ/h)                             1.59E+06              1.59E+06

Properties : D3 @COL1             Overall                Vapour Phase          Liquid Phase
Vapour/Phase Fraction                                0                     0                            1
Temperature: (C)                                 129.3                 129.3                        129.3
Pressure: (psig)                                    20                    20                           20
Molar Flow (kgmole/h)                               35                     0                           35
Mass Flow (kg/h)                                  3053                     0                         3053
Liquid Volume Flow (m3/h)                        3.493                     0                        3.493
Molar Enthalpy (kJ/kgmole)                   4.19E+04              7.86E+04                     4.19E+04
Mass Enthalpy (J/kg)                         4.80E+05              9.29E+05                     4.80E+05
Molar Entropy (kJ/gmole-C)                   -6.90E-02             -2.25E-03                    -6.90E-02
Mass Entropy (kJ/g-C)                        -7.91E-04             -2.65E-05                    -7.91E-04
Heat Flow (kJ/h)                             1.47E+06                      0                    1.47E+06

Properties : B3 @COL1             Overall                Vapour Phase          Liquid Phase
                                  Overall                Vapour Phase          Liquid Phase
Vapour/Phase Fraction                                0                     0                            1
Temperature: (C)                                 185.2                 185.2                        185.2
Pressure: (psig)                                    20                    20                           20
Molar Flow (kgmole/h)                               65                     0                           65
Mass Flow (kg/h)                                  7283                     0                         7283
Liquid Volume Flow (m3/h)                        8.327                     0                        8.327
Molar Enthalpy (kJ/kgmole)                        5852             4.19E+04                          5852
Mass Enthalpy (J/kg)                         5.22E+04              3.78E+05                     5.22E+04
Molar Entropy (kJ/gmole-C)                      0.1133                0.1996                       0.1133
Mass Entropy (kJ/g-C)                        1.01E-03              1.80E-03                     1.01E-03
Heat Flow (kJ/h)                             3.80E+05                      0                    3.80E+05




                                              – 89 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course


SUMMARY
Tray
Summary
Flow Basis:
Molar         Reflux Ratio: 2.493
              Temp.        Pressure      Liquid       Vapour         Feeds        Draws             Duties
              (C)           (psig)        (kgmole/h) (kgmole/h)      (kgmole/h)   (kgmole/h)        (KJ/h)
Condenser            129.3            20        87.25                                       35 L    -3.89E6
1__Main TS             135            20        86.57          122.3
2__Main TS           138.3            20         86.1          121.6
3__Main TS           140.5            20        85.41          121.1
4__Main TS           142.4            20        84.38          120.4
5__Main TS           144.6            20        83.02          119.4
6__Main TS           147.4            20        81.48           118
7__Main TS           150.6            20        80.02          116.5
8__Main TS             154            20        78.81            115
9__Main TS           157.1            20        77.91          113.8
10__Main TS          159.7            20        77.23          112.9
11__Main TS          161.8            20        76.67          112.2
12__Main TS          163.6            20        76.16          111.7
13__Main TS          165.2            20        177.6          111.2        100 L
14__Main TS          168.8            20        178.7          112.6
15__Main TS          171.5            20        179.4          113.7
16__Main TS          173.8            20        179.9          114.4
17__Main TS          175.8            20        180.3          114.9
18__Main TS          177.4            20        180.7          115.4
19__Main TS          178.9            20        181.1          115.7
20__Main TS          180.1            20        181.4          116.1
21__Main TS            181            20        181.7          116.4
22__Main TS          181.8            20        181.9          116.7
23__Main TS          182.4            20        182.1          116.9
24__Main TS            183            20        182.1          117.1
25__Main TS          183.5            20        182.1          117.1
26__Main TS          184.2            20        181.9          117.1
Reboiler             185.2            20                       116.9                        65 L    4.14E+06




                                               – 90 –
Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course




f. It is noted from the solution for (c) that the heat duty for the reboiler needed to meet the
   design specifications is 4.14E+06 KJ/h. If this value is reduced by 20%, that is, to
   3.312+06 KJ/h, then clearly, this new specification is substituted for one of the others. It
   is not possible to meet both of the product specifications simultaneously for the lower
   level of reboiler heat duty. The following table indicates the impact of possible alternative
   design specifications accounting for fouling. Note that cases B and C, in which one of the
   two product specifications is maintained leads to a serious reduction in the recovery of the
   species whose specification is sacrifices. In contrast, with case D, it is possible to back off
   both of the specifications simultaneously, and to recover at least 93% of both of the
   desired products even when the reboiler is fouled (20% less duty).

               Case          Specification 1     Specification 2             Outcome
                A               Toluene              o-Xylene        Base case design, with RR
                             recovery, 0.99      recovery, 0.994              = 2.493
                 B           Reboiler Duty,          o-Xylene          RR = 2.02, and toluene
                             3.312+06 KJ/h       recovery, 0.994      recovery drops to 0.862.
                 C           Reboiler Duty,          Toluene           RR = 1.03, and toluene
                             3.312+06 KJ/h        recovery, 0.99      recovery drops to 0.757.
                 D           Reboiler Duty,          o-Xylene          RR = 1.62, and toluene
                             3.312+06 KJ/h        recovery, 0.93      recovery drops to 0.931.




                                           – 91 –
      Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                          Exercise D.3 Solution using ASPEN.PLUS

9.1              Mass balances

                         Benzene         700 × 0.45 = D × 0.92 + B × 0.05
                         Overall               700 = D + B
                                 Solving:        D = 321.8 lbmole/hr, B = 378.2 lbmole/hr
                                                 L = R × D = 1.25 × 321.8 = 402.3 lbmole/hr
                                                    V = D + L = 321.8 + 402.3 = 724.1 lbmole/hr

                 Tower dimensions

                         Diameter
                               Vapor density – assume ideal gas at highest temperature = 227°F
                                             P               1 atm                     lbmole         lb
                                     ρv =      =             3
                                                                           = 0.001993        3
                                                                                               × 92
                                            RT             ft atm                         ft        lbmole
                                                   0.7302          × 687°R
                                                          lbmole°R
                                                                                     lb
                                                                            = 0.1834
                                                                                     ft 3
                                 Flooding velocity – see Example 10.2
                                                                                 1
                                                    ρ − ρV                         2
                                     U f = FST C F  L
                                                    ρ                       
                                                                             
                                                       V                    
                                                           0.2                           0.2
                                                  σ               18.2 
                                            FST =              =                           = 0.981
                                                   20             20 
                                                    Note: σ is for toluene at 227°F
                                                                     1                                        1
                                                Lρ                     2
                                                                               402.3  0.1834                    2
                                            FP =  V                        ≅               
                                                V  ρL
                                                  
                                                                 
                                                                              724.1  48.7 
                                                                             ≅ 0.0341

          Note: 48.7 is the density of toluene at 227°F

                                                     25.4 mm
                                         TS = 18 in ×          = 457.2 mm
                                                         in
                                         C F = 0.0105 + 8.127 × 10 −4 (457.2) e −1.463(0.0341)
                                                                                              0.842
                                                                             0.755


                                                                          m
                                             = 0.0105 + 0.0761 = 0.0866
                                                                           s
                                                                                                   1
                                                      48.7 − 0.1834                                  2
                                                                                                                      m        ft
                                 U f = 0.981 × 0.0866                                                    = 1.38       = 4.53
                                                           0.1834                                                   s        s
                                 U = 0.85 × 4.53 = 3.85 ft
                                                           s




                                                     – 92 –
Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                                                                                                  1
                                                                 lbmole           lb    1 hr 
                                                                                                      2

                               4V 
                                             1
                                                 2     4 × 724.1         × 92        ×       
                            D=                      =             hr         lbmole 3600 s 
                                         
                               0.9πρ vU                                      lb 
                                                            0.9(3.14)  0.1834 3  3.85
                                                                                        ft    
                                                                              ft     s     
                                                                                             
                                                     = 6.09 ft = 1.86 m
                   Height
                            H = 4 + (23 − 1) 1.5 + 10 = 47 ft = 14.3 m

           Costs
                   Column
                                   Eqs. (9.7) – FM = 1               (Fig. 9.3(c))

                                   C P = 1,780(14.3)             (1.86)1.23 = $38,640
                                                          0.87



                            From Figs 9.3(c) and 9.3(d) – FP = 1, FBM = 4.5
                                   CBM = 38,640 × 4.5 = $173,900

                   Trays
                            Figure 9.4 – fq = 1, Nact = 23, FBM = 1.2

                   CBM = [193.04 + 22.72(1.86) + 60.38(1.86)2] (1.2)(23)(1) = $12,300 / tray

                   Tower
                                   CBM = 173,900 + 12,300 = $186,200

                   Condenser
                                       lbmole               Btu                Btu
                            QC = 724.1          × 13,700          = 9.92 × 106
                                          hr              lbmole               hr
                            ∆TLM =
                                   (179 − 90) − (179 − 120) = 72.98°F
                                              179 - 90
                                          ln
                                              179 - 120
                                  9.92 × 10 6
                            AC =               = 1,360ft 2 = 126.3 m 2
                                 100 × 72.98

                        Eqs. (9.5)
                          C P = 450(126.3) = $13,300
                                           0.7


                        Fig. 9.1(a) - FM = 1 , Fig 9.1(b) - FP = 1 , Fig. 9.1(c) FBM = 3.2
                         C BM = 13,300 × 3.2 = $42,600




                                            – 93 –
Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course



                  Reboiler
                             Overall energy balance
                                     FH F + QR = DH D + QC + BH B
                                     QR = DH D + BH B + QC − FH F

                                Let H D = 0 (sat’d liq. at 179°F)
                                                        lbmole           Btu
                                     QR = 0 + 378.2             × 43.5           × (227 − 179 )°F
                                                             hr        lbmole°F
                                             + 9.92 × 10 6 − 700 × 39.4(201 − 179)
                                                          Btu
                                          = 10.1 × 10 6
                                                           hr
                                          10.1 × 10 6
                                      A=              = 842 ft 2 = 78.2 m 2
                                            12,000
                               Eqs. (9.5)
                                     C P = 450 (78.2 ) = $9,510
                                                         0.7


                              Fig. 9.1(a) - FM = 1 , Fig 9.1(b) - FP = 1 , Fig. 9.1(c) - FBM = 3.2
                                     C BM = 9,510 × 3.2 = $30,400

                   Reflux Accumulator
                                              lbmole          lb              lb
                                     V = 724.1       × 78          = 56,480         − ben. condensate
                                                 hr        lbmole             hr
                                                lb 1 ft 3            ft 3        ft 3
                                       = 56,480 ×            = 1,110      = 18.5
                                                hr 50.7 lb           hr          min
                                           Note: 50.7 is the density of benzene at 179°F

                                For a residence time = 5 min at half full:
                                    Volume = 18.5 × 10 = 185 ft 3 = 5.24 m 3
                                For L D = 4 :
                                               1            1
                                          V  3  5.24        3
                                     D=  =                      = 1.19 m
                                         π      π 
                                     L = 4.76 m

                                Fig. 9.3(a) − C P = $6,000
                                     9.3(c) − FM = 1, FP = 1
                                     9.3(d) − FBM = 3.0

                                     C BM = 6,000 × 3.0 = $18,000




                                              – 94 –
Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                   Reflux Pump – centrifugal

                            &     1          lbmole        lb    1 ft 3
                           Ws = m ∆P = 402.3
                                &                   × 78       ×        ×
                                  ρ            hr        lbmole 50.7 lb
                                               lb F      in 2   1 hr      1 W
                                             50     × 144 2 ×        ×
                                               in 2
                                                         ft   3,600 s 0.7376 ft ⋅ lb F
                                                                                 s
                                         = 1.7 KW

                           Figs. 5.49 – 5.51 – Ulrich

                                   CP = $3,800 , FM = 1, FP = 1, FBM = 3.2
                                   CBM = 3,800 × 3.2 = $12,200

                                                                           lbmole
                   Reboiler Pump – centrifugal − m = L + F = 402.3 + 700
                                                 &
                                                                             hr
                                                                        lbmole
                                                              = 1,102.3
                                                                          hr
                            &     1                    1      50 × 144
                           Ws = m ∆P = 1,102.3 × 92 ×
                                &                         ×                W
                                  ρ                   48.7 3,600 × 0.7376
                                     = 5.6 KW

                           Figs. 5.49 – 5.51 – Ulrich
                                    CP = $5,500 , FM = 1, FP = 1, FBM = 3.2
                                    CBM = 5,500 × 3.2 = $17,600

                   Total Bare Module Cost

                                                      Tower      186,200
                                                      Condenser 42,600
                                                      Reboiler   30,400
                                                      Reflux accumulator                  18,000
                                                      Reflux pump                12,200
                                                      Reboiler pump              17,600
                                                       $307,000 - mid-1982

                   In mid-1999:
                                              392
                           CTBM = 307,000 ×       = $382,000
                                              315




                                            – 95 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

Total Permanent Investment

                                CTBM                       =     382,000

                                Csite + Cserv = 0.1CTBM    =        38,200

                                       CDPI                                  $420,200

                                Ccont = 0.15 CDPI          =        63,000

                                       CTDC                                  $483,200

                                Cland = 0.02 CTDC          =         9,700
                                Croyal                     =           -
                                Cstart = 0.10 CTDC         =        48,300

                                       CTPI                                  $541,200 (mid-1999)




              IPE Results
                                                           IPE         Cost Charts in Chapter 9 – 1999 Costs

                   Distillation Tower

                   Diameter (ft)                              6.0                      6.09
                   Height (ft)                               47.0                      47.0
                   CP ($)                                  81,100            48,760×(392/315) = 60,700
                   CDML ($)                               214,000
                   CBM ($)                                                   186,200×(392/315) =231,700

                   Condenser

                   Area (ft2)                                 555                      1,360
                   CP ($)                                  15,000            13,300×(392/315) = 16,600
                   CDML ($)                                57,100
                   CBM ($)                                                   42,600×(392/315) = 53,000

                   Reboiler

                   Area (ft2)                             1,332.8                       842
                   CP ($)                                  26,900             9,510×(392/315) = 11,800
                   CDML ($)                                87,700
                   CBM ($)                                                    30,400×(392/315) =37,800

                   Reflux Accumulator

                   Volume (gal)                             719.8                       1,384

                                                – 96 –
Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                Diameter (ft)                             3.5                        3.9
                Height (ft)                                10                       15.6
                CP ($)                                 10,000              6,000×(392/315) = 7,500
                CDML ($)                               70,500
                CBM ($)                                                   18,000×(392/315) =22,400

                Reflux Pump

                Power (KW)                                 2.2                       1.7
                CP ($)                                  3,400              3,800×(392/315) = 4,700
                CDML ($)                               22,600
                CBM ($)                                                   12,200×(392/315) =15,200

                Reboiler Pump

                Power (KW)                                 7.5                       5.6
                CP ($)                                  4,500              5,500×(392/315) = 6,800
                CDML ($)                               32,100
                CBM ($)                                                   17,600×(392/315) =21,900


                           The equipment sizes and purchased costs are comparable with the
                           exception of the reboiler. IPE does not design for the heat flux of
                           12,000 Btu/hr ft2. IPE estimates the direct materials and labor costs,
                           CDML, for each equipment item. These estimates do not include the
                           indirect project expenses, while the bare module factors from the cost
                           charts include these expenses. Note, however, that the IPE estimates
                           of CDML are considerably higher than CBM for the reboiler and reflux
                           accumulator.

                   Total Permanent Investment

                           The total permanent investment is calculated in the table below. Note
                           that the purchased equipment cost, $145,800, is obtained from line 1
                           of the Contract Summary in the IPE Capital Estimate Report. The
                           total direct materials and labor costs are obtained from line 11,
                           $450,300 and $146,500, respectively. These sum to CDML = $596,800.
                           The direct installation cost is obtained by difference. The material and
                           manpower costs associated with G&A Overhead and Contract Fees
                           are obtained by adding the entries on lines 13 and 14; that is, $52,200 .
                           The Contractor Engineering and Indirect Costs are obtained from line
                           15.




                                            – 97 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course




                                                          Cost $         Source

IBL (Inside Battery Limits)
Purchased Equipment Cost                                    145,800 IPE Equipment List
Direct Installation Cost                                    451,000 By difference
  Total Direct Materials and Labor Cost, CDML =CDI          596,800 IPE Contract Summary
  Pipe Racks (10% of CDML)                                   59,700 Recommended by Instructor
  Sewers/Sumps (10% of CDML)                                 59,700 Recommended by
                                                                    Instructor
Mat’l and Labor G&A Overhead and Contract Fees               52,200 IPE Contract Summary
Contractor Engineering                                      390,400 IPE Contract Summary
Indirects                                                   358,900 IPE Contract Summary
IBL Total Bare Module Cost, CTBM                          1,517,700



                                                – 98 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course


OBL (Outside Battery Limits)
Site Preparation & Service Facil. (10% of CTBM)              151,800
Allocated Costs for Utilities                                      0
Storage                                                            0
Environmental                                                      0
OBL Total                                                    151,800

                Direct Permanent Investment, CDPI          1,669,500

Contingencies (15% of CDPI)                                  250,400

                    Total Depreciable Capital, CTDC        1,919,900

Land (2% of CTDC)                                             38,400
Royalty                                                            0
Start Up (10% of CTDC)                                       192,000

Total Permanent Investment, CTPI                           2,150,300


              Comparison of Results

                      Using the cost charts in Chapter 9, the total bare module cost, CTBM =
                      $382,000, as compared with the IPE estimate for the total direct materials and
                      labor cost of $596,800. This is partially due to the increase in reboiler area
                      due to IPE’s inability to design for a heat flux of 12,000 Btu/hr ft2. The
                      remaining difference is likely due to IPE’s detailed estimates of installation
                      costs.

                      Of greater consequence, the IPE estimate for the total permanent investment,
                      CTPI = $2,150,300, is substantially greater than that obtained using the cost
                      charts, $541,200. Although the IPE Project Type is Plant addition –
                      suppressed infrastructure, the IPE estimates for the contractor engineering
                      and indirect costs are substantial. These cause the total permanent investment
                      to far exceed that computed using the cost charts. This is probably because
                      the bare module factors in the cost charts are not sufficiently large to represent
                      the contractor engineering and indirect costs. However, some of the IPE
                      estimates may be large for this distillation plant, which has only six equipment
                      items. When added to the costs for more typical plants, with an order-of-
                      magnitude more equipment items, these large estimates would have a less
                      significant impact on the total permanent investment.




                                               – 99 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                                          Reactor Design

HYSYS.Plant

        The materials supporting a course in heat transfer assume that 2-3 hours of computer
laboratory time is allocated to the exercises. The multimedia includes a section that provides a
self-paced overview on reactors in general and the models available in HYSYS.Plant in
particular. The following sequence is suggested:

Session 1:   In the first part of the exercise session, the student should review the entire section
             on Reactors in the multimedia. This consists of modules describing all of the reactor
             models available in HYSYS.Plant, each illustrated by an example application. The
             students should ensure that they have covered the modules describing the PFR and
             the CSTR.




Session 2:   The tutorial Ammonia Converter Design should be reviewed, while at the same time,
             the student should develop his/her version of the simulation using HYSYS.Plant.




To reinforce their acquired capabilities, students should be assigned a homework exercise. A
typical exercise is provided.




                                              – 100 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                                          Reactor Design

ASPEN PLUS

        The materials supporting a course in heat transfer assume that 2-3 hours of computer
laboratory time is allocated to the exercises. The multimedia includes a section that provides a
self-paced overview on reactors in general and the models available in ASPEN PLUS in
particular. The following sequence is suggested:

Session 1:   In the first part of the exercise session, the student should review the entire section
             on Reactors in the multimedia. This consists of modules describing all of the
             reactor models available in ASPEN PLUS, each illustrated by an example
             application. The students should ensure that they have covered the modules
             describing the PFR and the CSTR.




Session 2:   The tutorial Ammonia Converter Design should be reviewed, while at the same time,
             the student should develop his/her version of the simulation using ASPEN PLUS.




To reinforce their acquired capabilities, students should be assigned a homework exercise. A
typical exercise is provided.




                                              – 101 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                               Exercise E.1 Reactor Design Problem

              Maleic anhydride is manufactured by the oxidation of benzene over vanadium
pentoxide catalyst (Westerlink and Westerterp, 1988), with excess air. The following reactions
occur:
        Reaction 1:       C6 H 6 + 9 O 2 → C 4 H 2O3 + 2CO 2 + 2H 2O
                                   2
                                                                                               (1)

        Reaction 2:    C4 H 2 O3 + 3O 2 → 4CO 2 + H 2 O                                        (2)

        Reaction 3:      C6 H 6 +   15
                                     2
                                         O 2 → 6CO 2 + 3H 2O                                   (3)

Since air is supplied in excess, the reaction kinetics are approximated as first-order rate laws:

                                               r1                 r2
                                     A                   P             B

                                          r3
                                                    C

                         r1 = k1C A ,r2 = k2C P and r3 = k3C A                                 (4)

In the above, A is benzene, P is maleic anhydride (the desired product), and B and C are the
undesired byproducts (H2O and CO2), with kinetic rate coefficients in s-1:
                            k1 = 4,300 exp [− 25,000 RT ] 
                                                          
                           k 2 = 70,000 exp [− 30,000 RT ]                                    (5)
                              k 3 = 26 exp [− 21,000 RT ] 
                                                          

In Eq. (5), the activation energies are in kcal/kgmol.


       The objective of this exercise is to design a plug flow reactor to maximize the yield of
MA, for a feed steam of 200 kgmol/hr of air (21 mol % O2 and 79 mol % N2) and 2 kgmol/hr of
benzene, at 200 oC and 1.5 Bar. Assume a reactor diameter of 2 m, neglect pressure drops, and
design for adiabatic operation.


    a) For fixed reactor tube length of 7 m, define the optimum reactor feed temperature to
       maximize MA yield (Hint: check values in the range 700-800 oC)
    b) Investigate the effect of both reactor tube length, in the range 5-15 m, and feed
       temperature, in the range 700-800 oC, on the MA yield. Define the optimum combination
       of both of these variables.

                   HYSYS.Plant Solution                            ASPEN PLUS Solution
                                                        – 102 –
     Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                             Exercise E.1 Solution using HYSYS.Plant

                            Solution reproduced in: REACT_EX_1.hsc


a)       The process is simulated using the Antoine equation for vapor pressure estimation (in the
         reaction conditions, the system is in the vapor phase, so that VLE calculations are not
         performed anyway). A PFD for the process is set up as below, noting that a heater, E-101,
         is installed to bring the reactor feed to the desired temperature.




         The Databook is used to investigate the sensitivity of yield (computed as the ratio of the
         molar flow rate of MA in PRODUCTS and the molar flow rate of benzene in S-2, 2
         kgmol/hr), and selectivity (computed as the ratio of MA in PRODUCTS and the molar
         flow rates in the same stream of the byproducts, H2O and CO2). A parametric run for a
         reactor of length 7 m is shown next.




                                                – 103 –
     Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

b)       It is noted that for a reactor tube length of 7 m, the optimal feed temperature appears to be
         780 oC; here the yield is just over 22% and the selectivity is about 16%. An additional
         sensitivity analysis, testing the variation of both feed temperature and reactor tube length,
         gives the following result:




         The peak in yield occurs approximately at a reactor tube length of 14 m, with a feed
         temperature of 710 oC. Complete results for these operating conditions are listed below.


Fluid Package: Basis-1
Property Package: Antoine

Plug Flow Reactor: PFR-100

PARAMETERS
Physical Parameters
                                                               Pressure Drop: 0.0000
Type : User Specified                                          bar
Heat Transfer : Heating
Type : Direct Q Value                 Energy Stream :          Duty : 0.0000 kcal/h
Dimensions
Total Volume: 43.98 m3                Length: 14.00 m          Diameter: 2.000 m     Number of Tubes: 1
Wall Thickness: 5.000e-003 m          Void Fraction: 1.0000    Void Volume: 43.98 m3
Reaction Info
                                                – 104 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

Reaction Set: Global Rxn Set           Initialize From: Current
Integration Information
                                       Minimum Step Fraction:     Minimum Step Length:
Number of Segments: 30                 1.0e-06                    1.4e-05 m


Length (m)                      Temperature (C)
                       0.233                      712.9
                          0.7                     715.9
                       1.167                      719.1
                       1.633                      722.3
                          2.1                     725.7
                       2.567                      729.2
                       3.033                      732.9
                          3.5                     736.8
                       3.967                      740.8
                       4.433                        745
                          4.9                     749.5
                       5.367                      754.2
                       5.833                      759.1
                          6.3                     764.4
                       6.767                      769.9
                       7.233                      775.9
                          7.7                     782.2
                       8.167                        789
                       8.633                      796.4
                          9.1                     804.3
                       9.567                        813
                      10.033                      822.6
                        10.5                      833.1
                      10.967                      844.9
                      11.433                      858.3
                        11.9                      873.6
                      12.367                      891.4
                      12.833                      912.6
                        13.3                      938.4
                      13.767                      971.2




                                                  – 105 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course



Mole Fractions
Length (m)       Oxygen        CO2             H2O            Benzene            MaleicAnhydr   Nitrogen
0.2333           0.2077        0.0001          0.0001         0.0098             0.0001         0.7822
0.7              0.2074        0.0002          0.0002         0.0098             0.0001         0.7822
1.167            0.2071        0.0004          0.0004         0.0097             0.0002         0.7822
1.633            0.2068        0.0005          0.0005         0.0097             0.0002         0.7823
2.1              0.2065        0.0007          0.0006         0.0096             0.0003         0.7823
2.567            0.2062        0.0008          0.0008         0.0095             0.0004         0.7823
3.033            0.2059        0.001           0.0009         0.0095             0.0004         0.7823
3.5              0.2056        0.0011          0.0011         0.0094             0.0005         0.7824
3.967            0.2052        0.0013          0.0012         0.0093             0.0006         0.7824
4.433            0.2048        0.0015          0.0014         0.0092             0.0006         0.7824
4.9              0.2044        0.0017          0.0016         0.0091             0.0007         0.7824
5.367            0.204         0.0019          0.0017         0.0091             0.0008         0.7825
5.833            0.2036        0.0021          0.0019         0.009              0.0009         0.7825
6.3              0.2031        0.0024          0.0021         0.0089             0.0009         0.7825
6.767            0.2026        0.0026          0.0024         0.0088             0.001          0.7825
7.233            0.2021        0.0029          0.0026         0.0087             0.0011         0.7826
7.7              0.2016        0.0032          0.0028         0.0086             0.0012         0.7826
8.167            0.201         0.0036          0.0031         0.0084             0.0013         0.7826
8.633            0.2003        0.004           0.0034         0.0083             0.0014         0.7826
9.1              0.1996        0.0044          0.0037         0.0082             0.0015         0.7827
9.567            0.1989        0.0048          0.004          0.0081             0.0016         0.7827
10.03            0.1981        0.0053          0.0043         0.0079             0.0017         0.7827
10.5             0.1971        0.0059          0.0047         0.0077             0.0018         0.7827
10.97            0.1961        0.0066          0.0052         0.0076             0.0019         0.7827
11.43            0.1949        0.0073          0.0056         0.0074             0.002          0.7827
11.9             0.1936        0.0082          0.0062         0.0072             0.0021         0.7827
12.37            0.1921        0.0093          0.0068         0.0069             0.0022         0.7827
12.83            0.1903        0.0106          0.0076         0.0066             0.0023         0.7827
13.3             0.188         0.0122          0.0085         0.0063             0.0023         0.7826
13.77            0.1852        0.0144          0.0096         0.0059             0.0024         0.7825


PROPERTIES
S-2                                           Overall                            Vapour Phase
Vapour/Phase Fraction                                                        1                                1
Temperature: (C)                                                          710                               710
Pressure: (bar)                                                            1.5                              1.5
Molar Flow (kgmole/h)                                                     202                               202
Mass Flow (kg/h)                                                        5926                              5926
Liquid Volume Flow (m3/h)                                               6.847                             6.847
Molar Enthalpy (kcal/kgmole)                                             5507                              5507
Mass Enthalpy (kcal/kg)                                                 187.7                             187.7
Molar Entropy (kJ/kgmole-C)                                               189                               189
Mass Entropy (kJ/kg-C)                                                  6.442                             6.442
Heat Flow (kcal/h)                                                  1.11E+06                          1.11E+06

                                              – 106 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

PRODUCTS                                      Overall                           Vapour Phase
Vapour/Phase Fraction                                                       1                               1
Temperature: (C)                                                        971.2                           971.2
Pressure: (bar)                                                           1.5                             1.5
Molar Flow (kgmole/h)                                                   201.9                           201.9
Mass Flow (kg/h)                                                         5926                            5926
Liquid Volume Flow (m3/h)                                               6.872                           6.872
Molar Enthalpy (kcal/kgmole)                                             5509                            5509
Mass Enthalpy (kcal/kg)                                                 187.7                           187.7
Molar Entropy (kJ/kgmole-C)                                             197.9                           197.9
Mass Entropy (kJ/kg-C)                                                  6.742                           6.742
Heat Flow (kcal/h)                                                  1.11E+06                        1.11E+06




                                              – 107 –
     Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

                                 Exercise E.1 Solution using ASPEN PLUS



a.                  The reactor is simulated using a 7 m tube length, with its feed temperature
                    varied between 700 and 800°C. The results below can be reproduced using the
                    file MA.BKP.


                       MIX-100                      E-101             PFR-100
            AIR


                                     S-1                    S-2                      PRODUCTS


          BENZENE




ASPEN PLUS Program
     TITLE 'MALEIC ANHYDRIDE MANUFACTURE'
     IN-UNITS MET VOLUME-FLOW='cum/hr' ENTHALPY-FLO='MMkcal/hr' &
             HEAT-TRANS-C='kcal/hr-sqm-K' PRESSURE=bar TEMPERATURE=C            &
             VOLUME=cum DELTA-T=C HEAD=meter MOLE-DENSITY='kmol/cum'            &
             MASS-DENSITY='kg/cum' MOLE-ENTHALP='kcal/mol' &
             MASS-ENTHALP='kcal/kg' HEAT=MMkcal MOLE-CONC='mol/l' &
             PDROP=bar
     DEF-STREAMS CONVEN ALL
     DESCRIPTION "
         General Simulation with Metric Units :
         C, bar, kg/hr, kmol/hr, MMKcal/hr, cum/hr.
         Property Method: None
         Flow basis for input: Mole
         Stream report composition: Mole flow
         "
     DATABANKS PURE11 / AQUEOUS / SOLIDS / INORGANIC / &
             NOASPENPCD
     PROP-SOURCES PURE11 / AQUEOUS / SOLIDS / INORGANIC
     COMPONENTS
         BENZENE C6H6 /
         MA C4H2O3 /
         WATER H2O /
         OXYGEN O2 /
         NITROGEN N2 /
         CO2 CO2
     FLOWSHEET
         BLOCK MIX-100 IN=AIR BENZENE OUT=S-1
         BLOCK E-101 IN=S-1 OUT=S-2
         BLOCK PFR-100 IN=S-2 OUT=PRODUCTS
     PROPERTIES IDEAL
     STREAM AIR
         SUBSTREAM MIXED TEMP=200. PRES=1.5 MOLE-FLOW=200.
         MOLE-FRAC OXYGEN 0.21 / NITROGEN 0.79
     STREAM BENZENE
         SUBSTREAM MIXED TEMP=200. PRES=1.5 MOLE-FLOW=2.
         MOLE-FRAC BENZENE 1.
     BLOCK MIX-100 MIXER
         PARAM PRES=1.5
     BLOCK E-101 HEATER
         PARAM TEMP=700. PRES=1.5
     BLOCK PFR-100 RPLUG
         PARAM TYPE=ADIABATIC LENGTH=7. <meter> DIAM=2. <meter> &
             PRES=1.5
         REACTIONS RXN-IDS=R-1
     EO-CONV-OPTI
     SENSITIVITY S-1
                                                – 108 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

       DEFINE FMAPR MOLE-FLOW STREAM=PRODUCTS SUBSTREAM=MIXED &
           COMPONENT=MA
       DEFINE FBENS2 MOLE-FLOW STREAM=S-2 SUBSTREAM=MIXED &
           COMPONENT=BENZENE
       DEFINE FWATPR MOLE-FLOW STREAM=PRODUCTS SUBSTREAM=MIXED &
           COMPONENT=WATER
       DEFINE FCO2PR MOLE-FLOW STREAM=PRODUCTS SUBSTREAM=MIXED &
           COMPONENT=CO2
   F     SELEC = FMAPR/(FWATPR + FCO2PR)
   F     YIELD = FMAPR/FBENS2
       TABULATE 1 "SELEC" COL-LABEL="SELEC"
       TABULATE 2 "YIELD" COL-LABEL="YIELD"
       VARY BLOCK-VAR BLOCK=E-101 VARIABLE=TEMP SENTENCE=PARAM
       RANGE LOWER="700" UPPER="800" INCR="5"
   STREAM-REPOR MOLEFLOW
   REACTIONS R-1 POWERLAW
       REAC-DATA 1 PHASE=V
       REAC-DATA 2 PHASE=V
       REAC-DATA 3 PHASE=V
       RATE-CON 1 PRE-EXP=4300. ACT-ENERGY=25000. <kcal/kmol>
       RATE-CON 2 PRE-EXP=70000. ACT-ENERGY=30000. <kcal/kmol>
       RATE-CON 3 PRE-EXP=26. ACT-ENERGY=21000. <kcal/kmol>
       STOIC 1 MIXED BENZENE -1. / OXYGEN -4.5 / MA 1. / CO2 &
           2. / WATER 2.
       STOIC 2 MIXED MA -1. / OXYGEN -3. / CO2 4. / WATER &
           1.
       STOIC 3 MIXED BENZENE -1. / OXYGEN -7.5 / CO2 6. / &
           WATER 3.
       POWLAW-EXP 1 MIXED BENZENE 1. / MIXED OXYGEN 0. / MIXED &
           MA 0. / MIXED CO2 0. / MIXED WATER 0.
       POWLAW-EXP 2 MIXED MA 1. / MIXED OXYGEN 0. / MIXED CO2 &
           0. / MIXED WATER 0.
       POWLAW-EXP 3 MIXED BENZENE 1. / MIXED OXYGEN 0. / MIXED &
           CO2 0. / MIXED WATER 0.

                  Stream Variables
AIR BENZENE PRODUCTS S-1 S-2
 ----------------------------

 STREAM ID                  AIR          BENZENE        PRODUCTS    S-1         S-2
 FROM :                     ----         ----           PFR-100     MIX-100     E-101
 TO   :                     MIX-100      MIX-100        ----        E-101       PFR-100

 SUBSTREAM: MIXED
 PHASE:                     VAPOR        VAPOR          VAPOR        VAPOR       VAPOR
 COMPONENTS: KMOL/HR
   BENZENE                   0.0          2.0000      1.7957          2.0000      2.0000
   MA                        0.0          0.0         0.1817          0.0         0.0
   WATER                     0.0          0.0         0.4312          0.0         0.0
   OXYGEN                   42.0000       0.0        41.0127         42.0000     42.0000
   NITROGEN                158.0000       0.0       158.0000        158.0000    158.0000
   CO2                       0.0          0.0         0.4991          0.0         0.0
 TOTAL FLOW:
   KMOL/HR                 200.0000       2.0000    201.9205        202.0000    202.0000
   KG/HR                  5770.0794     156.2273   5926.3067       5926.3067   5926.3067
   CUM/HR                 5245.2337      52.4523   1.1505+04       5297.6860   1.0896+04
 STATE VARIABLES:
   TEMP    C               200.0000     200.0000    754.7921        200.0000    700.0000
   PRES    BAR               1.5000       1.5000      1.5000          1.5000      1.5000
   VFRAC                     1.0000       1.0000      1.0000          1.0000      1.0000
   LFRAC                     0.0          0.0         0.0             0.0         0.0
   SFRAC                     0.0          0.0         0.0             0.0         0.0
 ENTHALPY:
   KCAL/MOL                  1.2291     24.3408       5.3789          1.4579      5.3768
   KCAL/KG                  42.6010    311.6074     183.2702         49.6925    183.2702
   MMKCAL/HR                 0.2458   4.8682-02       1.0861          0.2945      1.0861
 ENTROPY:
   CAL/MOL-K                 3.4826     -26.4277        9.4157       3.2968      8.9069
   CAL/GM-K                  0.1207      -0.3383        0.3208       0.1124      0.3036
 DENSITY:
   KMOL/CUM               3.8130-02   3.8130-02    1.7551-02       3.8130-02   1.8539-02

                                              – 109 –
   Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

  KG/CUM                     1.1001       2.9785          0.5151     1.1187         0.5439
AVG MW                      28.8504      78.1136         29.3497    29.3382        29.3382


                  Selected Process Unit Output
BLOCK: PFR-100 MODEL: RPLUG
 -----------------------------
                           *** INPUT DATA ***
   REACTOR TYPE:
     ADIABATIC
     VAPOR FLUID PHASE
   REACTOR TUBE LENGTH                  METER                           7.0000
                 DIAMETER               METER                           2.0000
   NUMBER OF REACTOR TUBES                                              1
   REACTOR VOLUME                       CUM                             21.991


                              ***    RESULTS   ***
   REACTOR DUTY                MMKCAL/H                                 0.00000E+00
   RESIDENCE TIME              HR                                       0.19685E-02
   REACTOR MINIMUM TEMPERATURE C                                        700.00
   REACTOR MAXIMUM TEMPERATURE C                                        754.79


            *** RESULTS PROFILE (PROCESS STREAM) ***
       LENGTH          PRESSURE         TEMPERATURE       VAPOR FRAC      RES-TIME
       METER           BAR              C                                 HR

       0.00000E+00      1.5000           700.00            1.0000        0.00000E+00
       0.70000          1.5000           704.18            1.0000        0.20124E-03
        1.4000          1.5000           708.57            1.0000        0.40166E-03
        2.1000          1.5000           713.18            1.0000        0.60121E-03
        2.8000          1.5000           718.06            1.0000        0.79980E-03
        3.5000          1.5000           723.22            1.0000        0.99742E-03
        4.2000          1.5000           728.70            1.0000        0.11940E-02
        4.9000          1.5000           734.54            1.0000        0.13894E-02
        5.6000          1.5000           740.81            1.0000        0.15837E-02
        6.3000          1.5000           747.52            1.0000        0.17768E-02
        7.0000          1.5000           754.79            1.0000        0.19685E-02


            ***   TOTAL MOLE FRACTION PROFILE (PROCESS STREAM) ***

       LENGTH          BENZENE          MA                WATER           OXYGEN
       METER
       0.00000E+00     0.99010E-02      0.00000E+00       0.00000E+00     0.20792
       0.70000         0.98209E-02      0.76249E-04       0.16503E-03     0.20755
        1.4000         0.97375E-02      0.15496E-03       0.33777E-03     0.20717
        2.1000         0.96503E-02      0.23630E-03       0.51903E-03     0.20676
        2.8000         0.95588E-02      0.32064E-03       0.71030E-03     0.20634
        3.5000         0.94628E-02      0.40802E-03       0.91208E-03     0.20588
        4.2000         0.93616E-02      0.49880E-03       0.11262E-02     0.20540
        4.9000         0.92548E-02      0.59306E-03       0.13535E-02     0.20489
        5.6000         0.91416E-02      0.69119E-03       0.15963E-02     0.20434
        6.3000         0.90214E-02      0.79328E-03       0.18559E-02     0.20375
        7.0000         0.88931E-02      0.89979E-03       0.21357E-02     0.20311
       LENGTH          NITROGEN         CO2
       METER
       0.00000E+00     0.78218          0.00000E+00
       0.70000         0.78221          0.17757E-03
        1.4000         0.78224          0.36562E-03
        2.1000         0.78226          0.56546E-03
        2.8000         0.78229          0.77933E-03
        3.5000         0.78233          0.10081E-02
        4.2000         0.78236          0.12549E-02
        4.9000         0.78239          0.15208E-02
        5.6000         0.78242          0.18102E-02

                                               – 110 –
     Materials for Participants – Module Instruction Sequence and Problem Statements by Core Course

          6.3000         0.78245            0.21252E-02
          7.0000         0.78249            0.24719E-02

        The variation of the selectivity (ratio of maleic anhydride in the product stream to the sum
of the water and CO2 in the product stream) and the yield (ratio of maleic anhydride in the
product stream to the benzene in stream S-2) are graphed as a function of the reactor feed
temperature:

                                            Sensitivity S-1 Results Summary




                                     0.25
                              0.2
                              0.15


                                     0.2
                                     0.15
                              0.1
                              0.05


                                     0.1




                                                               SELEC
                                                               YIELD
                              0




                                     700       725      750     775   800
                                            VARY 1 E-101 PARAM TEMP C


Note that for a reactor tube length of 7 m, the yield is a maximum at approximately 780°C.

b.                  Results are not presented for the variation with the reactor length.




                                                  – 111 –

				
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